How did eucalyptus trees get to california
Eucalyptus: How California's Most Hated Tree Took Root
Depending on whom you ask, eucalyptus trees are either an icon in California or a fire-prone scourge.
Bay Curious heard from two hikers wanting to know about the past and future of California’s eucalyptus trees.
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“How did all of this eucalyptus get to the Bay Area?” asked Christian Wagner, a tech worker who lives in Pleasanton.
“I know that they’re invasive, so what do we do about that? Are they worth keeping around? Or do we need to get rid of them and replace them with something else?” wondered Julie Bergen, an occupational therapist from Alameda.
Reaching heights of more than 100 feet, the main kind of eucalyptus you’re likely to see here is Tasmanian blue gum, eucalyptus globulus. They feature sickle-shaped leaves hanging from high branches, and deciduous bark that is forever peeling from their shaggy trunks. Some people experience the smell of eucalyptus as medicinal; others say the trees just smell like California.The trees are deciduous, shedding their bark every year. (Samantha Shanahan/KQED)
So how did eucalyptus trees get here?
“They came here as envelopes of seeds on boats coming to California in the 1850s,” explains Jared Farmer, author of "Trees In Paradise: A California History."
During the Gold Rush, Australians were among the throngs flocking to a place where wood was in short supply.The predominantly Australian eucalyptus genus includes more than 700 species, ranging from tall trees to shrubs. Hundreds have been tried out in California, but only red gum and blue gum reproduce on their own here.
“This was the era of wood power,” Farmer says. “Wood was used for almost everything. For energy, of course, but also for building every city, for moving things around, all the things where today we use concrete and plastic and steel.”
Besides the practical need to plant more trees, settlers who were used to dense forests also felt that the lack of trees in California’s grassy, marshy, scrubby landscape made it feel incomplete. So within a few years, nurseries in San Francisco were selling young eucalyptus grown from seed.
The trees grew remarkably quickly here, even in poor soil.
“In an average rainfall year here in California, these trees probably put on 4 to 6 feet in height and maybe, in their early growth years, a half-inch to an inch in diameter,” says Joe McBride, a UC Berkeley professor emeritus of landscape architecture and environmental planning.
Beyond the drive to change the landscape and provide firewood, Californians also planted eucalyptus (mainly blue gum) to serve as windbreaks.Eucalyptus trees grow fast, sometimes putting on 4 to 6 feet in height in a single year. (Samantha Shanahan/KQED)
In fact, that was the original purpose of what’s now the largest, densest stand of blue gum eucalyptus in the world, on campus at Berkeley, says McBride. It was planted around 140 years ago to provide a windbreak for an old cinder running track -- to keep its fine ashen gravel from blowing into athletes’ faces.
The trees’ success in California owed to a lack of enemies here. Because they were grown from seed, they hadn’t brought along any of the pests or pathogens (or koalas) they contend with back in Australia.
An early 20th century boom
Within a few decades of its arrival, many Californians grew disenchanted with eucalyptus. Blue gum proved terrible for woodworking — the wood often split and cracked, making it a poor choice for railroad ties. The trees also proved thirsty enough to drain nearby wells.
“If you go back to California farm journals of the 1870s, '80s, '90s, there’s just report after report of disappointment, like ‘these trees are no good,’ ” says Farmer, the historian.
But things changed in the early 20th century when U.S. Forest Service officials grew concerned about a looming timber famine. They feared forests in the eastern United States had been overexploited and wouldn’t grow back, and predicted the supply of hardwood would dwindle over the next 15 years.The bark sheds often, peeling in large strips. (Samantha Shanahan/KQED)
Investors saw an opportunity: California had a tree capable of growing to full size within that time frame. If hardwood was about to be scarce, they reasoned, such trees could be in high demand and yield sizable returns within a few short years. (These people, Farmer says, were not reading blue gum’s lousy reviews in old farm reports. “And even if they did read them, maybe they wouldn’t care because they just wanted to make a buck; they were just flipping land.”)
This played out as a speculative frenzy — a bubble. Boosters began selling plantations dense with eucalyptus — hundreds of trees per acre. Farmer writes in his book that claims were made like: “Forests Grown While You Wait,” and “Absolute Security and Absolute Certainty.” In just a few years, millions of blue gums were planted from Southern California up to Mendocino.
The anticipated timber famine never came to pass. Forests further east proved more resilient than expected, and the need was offset by concrete, steel and imports, like mahogany. Ultimately, the thousands of acres of eucalyptus planted around California were not even worth cutting down. Much of what you see today is a century-old abandoned crop.
What’s fire got to do with it?
Eucalyptus trees have lovers and haters in California. A big part of the debate over whether the trees should be allowed to persist here traces back to the East Bay firestorm of 1991, which left 25 people dead and thousands homeless. Vast swaths of eucalyptus burned.
“People at the time, I don’t think, associated that with a planted plantation; it was just a eucalyptus forest,” says CalPoly botanist Jenn Yost. “And then when the fire came through — I mean that fire came through so fast and so hot and so many people lost their homes that it was a natural reaction to hate blue gums at that point.”
Because the trees shed so much bark, critics argue they worsen the fire hazard and should be cut down. Defenders point out California’s native plants also have a tendency to burn. Both say the science is on their side, but so far no landmark study has shut down the dispute.
That ongoing dispute is also politically entrenched. A few years ago, federal funding to cut down trees in the East Bay hills was rescinded, after protesters got naked and hugged the eucalyptus trees on campus at Cal.To some, the scent of eucalyptus trees is simply the scent of California. (Samantha Shanahan/KQED)
Are they here to stay?
Blue gums can’t reproduce on their own just anywhere in California; Yost says they need year-round moisture. They’re able to regenerate in places like California’s coastal fog belt, but elsewhere “there are some plantations that don’t reproduce at all. When you go there, the trees are all in their rows, there’s few saplings anywhere to be seen, and those trees are just getting older.”
Not all non-native plants capable of reproducing on their own do it enough to have an ecological impact, Yost says.
“As soon as it starts outcompeting native species or fundamentally changing the environment so that native species can’t grow there, we would consider that an invasive species," she says.
Blue gum is classified as a “moderate” invasive, putting it a tier below such uncharismatic weeds as yellow star-thistle and medusahead. McBride, the retired Berkeley professor, says “although there’s been marginal expansion of some eucalyptus stands, it’s really not well adapted for long-distance dispersal. It hasn’t really spread very much on its own.”
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With an estimated 40,000 of eucalyptus planted across the state, the trees aren’t easy to get rid of. Slicing down a large blue gum near a building can require a crane, at an expense of thousands of dollars. And keeping them from resprouting can also be its own chore.
Long term, as the climate changes over the coming decades, it's possible the aging eucalyptus groves that don’t get enough water to reproduce will begin to die.
Then again, if the state becomes hotter and drier, it may become the type of place where some Australian species are able to thrive.
How the Eucalyptus Came to California
It seems harmless enough; how can releasing just a few plants or animals into a new area hurt anything? But again and again, we’ve seen just how devastating introducing a foreign organism can be, whether it was on purpose or inadvertent. This has led to declining populations of bats, honeybees, and amphibians, among others, and explosive population increases among garden snails in California. Even when it doesn’t look like the non-native organism is doing any harm, it’s still tilting a biological scale that had carefully balanced itself over millennia.The blue gum (<em>Eucalyptus globulus</em>) has become embedded in much of California's scenery, though how this came to be is a cautionary tale that emphasizes the importance of thinking before planting.Courtesy Photo
When we think of organisms being introduced to new lands and wreaking havoc upon the natives, animals more readily come to mind than plants do. But the often over-looked plant invaders have significantly sculpted the California landscape to become what we know it to be today. Europeans started to settle in California in the late 1700s, and soon many non-native plant species made their way to California as well. By the early 1800s, there were 16 non-native plant species, but this jumped to about 134 species by 1860. The number has been increasing ever since; today, there are over 1,000 non-native plant species living in California (and nearly 5,000 native species). While less than 10 percent of these non-native plants are considered to be a “serious threat” to native organisms, every new plant affects its environment in ways both subtle and profound.
Introducing “aliens”: Just how much damage can a few non-native plants do? A great deal. For example, they compete with native plants for nutrients. They can in some cases alter nutrient levels in the soils (such as nitrogen levels) such that the entire local environment becomes changed and undesirable for native plants and animals. This can in turn prompt even more non-native plants, animals, and microorganisms to become established in these “disrupted” areas. The entire ecosystem’s balance can be thrown off.
While not all non-native plants and animals cause such noticeable damage to their new environments, the potential for serious disruption is always present, and each should be introduced with premeditation and educated planning. The story of how the eucalyptus came to be embedded in much of California’s scenery is a great example of lack of forethought when introducing a plant to a new area.
Australian roots: In 1770, eucalyptus specimens made their way to Europe for the first time. On his first Pacific Ocean trip, Captain James Cook explored part of the Australian coast. Botanists onboard catalogued and collected several different species along the way, taking them back to London. European botanists gave the trees the name “eucalyptus” because of how the flowers are in hard, protective cup-like structures: The Greek root “eu” means “well” and “calyptos” means “covered.”
Soon, interest in the eucalyptus swelled in Europe. In the early 1800s, wealthy merchants and aristocrats were excited about rare or “exotic” plants and, together with people in the plant business, made cultivating eucalyptus trees popular. Horticulturists also wanted to better study such novelties, to understand them scientifically and see what their potential economic value might be. And of course, the new European settlers in Australia were eager to make some money selling the abundant eucalyptus. Promoters touted the trees as not only aesthetically pleasing, but as capable of satisfying many practical needs. The eucalyptus quickly spread in Europe.
Eucalyptus is a very large genus that consists of over 600 species, which natively live in Australia, Tasmania, and some surrounding islands, in a range of soil conditions and temperatures (though prolonged frost is usually detrimental). They do very well in Australia; 80 percent of Australia’s open forests are eucalyptus trees. With some aromatic species majestically soaring over 300 feet tall, as a hardwood tree their height is second only to California’s coastal sequoias. It’s easy to see their appeal.
On an economic level, many early promoters believed the eucalyptus could be used for making a number of materials: timber, fuel, medicine, wood pulp, honey, and both medicinal and industrial oils. Not only could eucalyptus grow quickly in many conditions, but, in several species, when the tree’s cut down even to the roots new stems sprout back up. It all seemed too good to be true. Later, it turned out, it was.
The eucalyptus goes to California: Following its spread throughout Europe, northern Africa, India, and South America, settlers in California became increasingly interested in the eucalyptus. Not only was eucalyptus a fascinating novelty, but the California Gold Rush of the late 1840s and early 1850s created high demand for wood for constructing buildings and for fuel. Deforestation had become a serious concern, so much so that the California Tree Culture Act of 1868 was created to encourage people to plant more trees, particularly along roads. Many entrepreneurs rushed to capitalize on the situation.
Ellwood Cooper’s role in spreading eucalyptus: Ellwood Cooper, educator, entrepreneur, and one of the key individuals who helped the eucalyptus take off in California, is a local legend here in Santa Barbara. After seeing eucalyptus in the San Francisco area, Cooper settled down in Santa Barbara in 1870. On his ranch, among many different types of produce trees (including olives, walnuts, and figs), he grew over 200 acres of eucalyptus. The eucalyptus forest he started lives on to this day at the Ellwood Bluffs. Cooper became a vocal advocate for the eucalyptus, emphasizing its unique, aesthetically pleasing appearance, as well as its useful qualities. He even wrote the first book in the U.S. on the trees. Eucalyptus became very appealing to foresters in the 1870s and 1880s as native hardwoods were being severely depleted.
Starting in the 1870s, the first large-scale commercial planting of the blue gum eucalyptus (E. globulus) began. The blue gum, a mid-sized eucalyptus reaching around 150 to over 200 feet tall, is the most common eucalyptus in California. These trees are easily recognized by their waxy blue leaves and a grayish bark which reveals a smooth, contrasting yellowish surface when the bark sheds off in long strips. As with many other eucalyptus species, sprouts can grow back from a fallen tree stump.
By the early 1900s, the get-rich mindset had caused many aspiring forest tycoons to plant countless acres of eucalyptus in hopes of selling the timber for a tidy profit. It’s estimated that there were over 100 companies involved in the eucalyptus industry at this time, and they changed the landscape of much of California.
But investors were soon to discover that the eucalyptus weren’t all they’d hoped them to be.
Sadly, most of these schemes went the way they infamously did for Frank C. Havens. Havens was an Oakland developer who opened a mill and planted eight million eucalyptus trees in a 14-mile-long strip from Berkeley through Oakland. But when he came to sell the timber, it was found that the trees were too young to make suitable wood; the young wood had an irregular grain and it bent, cracked, and shrank when dried. It is true that eucalyptus trees from Australia could make good timber, but those trees were decades or sometimes centuries old. It was soon found that eucalyptus trees would need to be at least 75 or 100 years old for good lumber. The young wood didn’t even make useable fence posts or railroad track ties, both of which decayed rapidly. Havens closed shop.
Other options for selling California-based eucalyptus products were grim. In the early 1920s, it was realized that California eucalyptus oil wasn’t nearly the same quality as foreign-made oil, again mainly from Australia. The wood became increasingly sold just for fuel, but cheap electricity and gas soon replaced it. By 1950, eucalyptus trees were primarily grown in California as ornamentals or windbreaks. The trees had failed to live up the many premature claims and hopes.
Eucalyptus recently: Today, millions of acres globally are covered by eucalyptus, as forests, shade trees, anchors along canals, ornamentals, windbreaks, or plantations. Their adaptability allows them to grow where other plants can’t, such as lands that have been ruined by mining or poor agricultural practices. They’re still used in medical products (including antiseptics, decongestants, and stimulants), foods (such as cough drops and sweets), perfumes, toothpastes, industrial solvents, menthol cigarettes, and more. (But be careful, because eucalyptus bark and leaves, and consequently eucalyptus oil, are toxic if ingested or absorbed through the skin at high doses. It’s especially poisonous to cats.) Eucalyptus is also a source of quality pulp. In a controversial case of history potentially repeating itself, these factors have caused eucalyptus plantations to crop up in many developing countries, particularly in Thailand. Due to the contentious social and environmental impacts of this, much criticism has been cast upon the international corporations spearheading these projects.
In addition to these new plantations, there are other divisive issues surrounding the eucalyptus today. Blue gum can be invasive in California, aggressively spreading from its original planting if enough water is present, such as in the form of fog. The bark strips dropped by the blue gums are extremely flammable, which can lead to intense fires, such as the Oakland Firestorm of 1991.
Additionally, in eucalyptus groves outside of their native homes, ecosystem development faces many challenges. Because most eucalyptus trees were grown from seeds from Australia, few eucalyptus insect pests traveled with the eucalyptus to their new homes. Fifty-seven Australian mammal species that normally live in eucalyptus groves, including koalas, wallabies, and pandemelons, as well as over 200 bird species, didn’t make the voyage either. Because the eucalyptus leaves and bark are poisonous, the mammals that feed off of it had to evolve mechanisms to deal with these toxins. Other mammals won’t eat the eucalyptus. Overall, this results in a small degree of species diversity in eucalyptus groves. Australian plants and animals never arrived; native plants and animals are pushed out. While the eucalyptus is certainly not as devastating to its new home as some non-native plants and animals have been, its story should still serve as a cautionary tale: Think before you plant.
For more on eucalyptus and non-native plants, see Robin W. Doughty’s book The Eucalyptus: A Natural and Commercial History of the Gum Tree, Carla C. Bossard, John M. Randall, and Marc C. Hoshovsky’s book on Invasive Plants of California’s Wildlands, California Invasive Plant Council’s website on Invasive Plant Inventory, the University of California’s Agriculture and Natural Resources’ website on Invasive Plants, California’s Department of Fish and Game website on Invasive Species Program, a previous Santa Barbara Independent article on Ellwood Cooper and other Santa Barbara Pioneer Horticulturists, and Wikipedia’s article on Eucalyptus.
Biology Bytes author Teisha Rowland is a science writer, blogger at All Things Stem Cell, and graduate student in molecular, cellular, and developmental biology at UCSB, where she studies stem cells. Send any ideas for future columns to her at [email protected]
The most devastating infection is spreading right now. But few people have heard of it
© Marek R. Swadzba/Shutterstock/Fotodom
Fungal infections sometimes affect humans, but the truly catastrophic damage is done to plants and animals. Chytridiomycosis has already wiped out dozens of amphibian species and threatens hundreds of others, chestnut blight has changed the face of the US East Coast, and millions of bats have died from white nose syndrome in just a few years. Regardless, the next killer fungus is sure to take us by surprise.0003
Old American cartoons, such as Popeye the Sailor, Tom the Cat and Jerry the Mouse, have something strange - bananas. They look thicker and less rounded than in real life. Perhaps the animators proceeded from technical limitations or some artistic ideas. However, it may also be that the cartoons depict fruits that almost none of us have tried.
Bananas are very different, but for export, including to Russia, almost always the same variety goes - "Cavendish". True, it was not always so. Under 19In the 60s, the most common variety was "Gros Michel". It was he who was drawn in cartoons of the first half of the 20th century.
Gros Michel bananas
While Gros Michel bananas do sometimes look straighter and thicker than Cavendish bananas, it is not so easy to tell them apart by eye. In many ways, this is why one variety has replaced another: people choose the familiar. But it is also believed that "Gros Michel" has a richer taste and a more pleasant, creamy texture. These bananas would still be sold all over the world if the "Gros Michel" had not almost completely died out.
Whether it was necessary to draw bananas straight and thick or not, some recognizable details appeared in the animation just like that. For example, the white gloves of Mickey Mouse and other characters. It is usually said that with gloves you do not need to work out the joints of the fingers - this simplifies the work. It is also not necessary to do this without gloves. Another thing is more important: they are better seen against a dark background and give animals a resemblance to humans. In addition, in the 1920s and 1930s, audiences increasingly preferred screenings to theater productions, and white gloves reminded them of vaudeville, where white actors dressed as blacks played mischievous but good-natured characters. Yes, this wardrobe item is also an echo of the racist past.
"Gros Michel" killed one of the strains of the fungus Fusarium oxysporum . The disease it causes, which causes plants to rot from the inside, was first described in 1876 in Australia. A few years later, the fungus made its way to Central America, where it caused one of the largest epidemics - or rather, epiphytoties, since we are not talking about people - in the history of agriculture. The disease was called Panamanian.
Shortly after Panama disease made Gros Michel exotic and Cavendish became the main banana for export to distant lands, the two varieties showed another similarity. At 19In the 1960s, another species of the fungus F. oxysporum began to devastate plantations, first in Taiwan, then in other countries of Southeast Asia, and recently appeared in Africa and Australia. The causative agent (for brevity it is designated TR4) was identified only in 1994. So far, there is nothing to replace the Cavendish, which faces the same fate as the Gros Michel.
Panama disease banana plantation in Costa Rica, 1919
© The Library of Congress/Public Domain/Wikimedia Commons
Fungal infections brought great trouble even before the Panama disease. But it seems that outbreaks are happening more and more often, there are many sad similarities between them, not only plants, but also animals are sick, and people may not notice a pestilence that exterminates dozens of species for years.
How plants get sick
Historically, fungi and fungi-like microorganisms, oomycetes, have been the most damaging to plants. Sometimes the damage was so great that a person suffered next. In the middle of the 19th century, potatoes infected with Phytophthora infestans . The crops failed time after time. The Irish had a particularly hard time: a terrible famine broke out on the island. According to one estimate, one in eight inhabitants died between 1841 and 1851, and the same number emigrated.
On this topic
The total population of the Republic of Ireland and Northern Ireland is still smaller than it was before the famine, and the reasons for it are still being debated. So, in March 2021, US President Joe Biden, discussing his migration policy, remembered his great-grandfather, who sailed to North America on a "coffin ship". According to Biden, the British were to blame for the famine.
Phytophthora is still destroying potato crops. A decade ago, scientists in the UK and the US tried to estimate how much food is wasted every year due to it, as well as fungal infections in rice, wheat, corn and soybeans. Using data from the Food and Agriculture Organization of the United Nations (FAO) on harvests for the 2009-2010 season, the researchers calculated that this food would be enough for at least 596 million people. They also considered the unlikely scenario where all five crops are hit by severe "epidemics" at the same time. In this case, the lost would be enough for 4.3 billion people. Such a coincidence would be a disaster.
Although the calculations turned out to be impressive, something in cereals and potatoes makes it difficult to look at their diseases as a real pestilence. Perhaps the fact is that these are plants that die this way and that way in the fall. The only difference is whether they manage to be useful or create another problem: income, food, or something else.
But fungi do not only affect cultivated fields. In the first half of the 20th century, an infection almost completely wiped out chestnut trees on the East Coast of the United States. It is believed that the fungus that causes it Cryphonectria parasitica entered with seedlings from Japan. In Asia, trees coexisted with the pathogen for centuries, but American chestnuts were defenseless against it.
The diseased tree was first noticed at the New York Zoo in 1904, from where the disease quickly spread throughout the eastern states. Chestnuts were treated with chemicals, whole groves were cut down and burned if a fungus was noticed in them. It didn't work. By 1940, more than 3.5 billion chestnut trees, which previously determined the appearance of those regions, had died.
Cryphonectria parasitica chestnut leaves
© Nick Greaves/Shutterstock/Fotodom
Chestnut rot in the eastern United States is one of the most devastating, but by no means the only, tree epiphytotics in recent times. By the end of the 20th century, there were almost no mature elms left in the UK: due to a particularly virulent strain of the fungus Ophiostoma ulmi , 25 million trees died (in the USA - 77 million). Fungus Phytophthora ramorum killed at least 1.4 million oak trees in California, and in the UK, because of it, 4 million larches were cut down for prevention. In western Australia, another blight, P. cinnamomi , has killed eucalyptus and other plants over 1 million hectares. And the beetles that infect trees with the help of the fungus Grosmania clavigera destroyed 16.3 million hectares of forest in Canada - this is slightly less than the area of Primorsky Krai.
The same British-American research team that estimated crop losses also calculated damage from tree diseases. According to their estimates, by 2020 dead trees could absorb 230-580 million tons of carbon dioxide from the air. Compared to 34.9billion tons emitted into the atmosphere in 2021, it seems like a drop in the ocean. But it is worth remembering that by the early 2030s, we are very likely to have exhausted the "carbon budget" allocated to ensure that the average temperature on the planet has not risen by more than 1.5 ° C since pre-industrial times. Then hundreds of millions of tons of carbon dioxide do not seem such a small thing.
How animals get sick
In 2006, something went wrong with bats in a cave in New York State. Some woke up early from hibernation, others lay dead almost or completely without the fat layer that they need to overwinter and produce offspring in the spring. There was a fungal coating on the muzzles, ears and wings. Later, the fungus will be called in Latin Pseudogymnoascus destructans , and the disease is white nose syndrome.
Fungal infections in animals are relatively rare and usually affect individuals with weakened immune systems. First, the scientists checked whether the bats were sick with something else and whether there was something else harmful in the cave. Then they caught healthy animals, brought them to the laboratory and infected them with a fungus isolated from the sick. So it became clear that it is P. destructans that causes the disease.
© Marvin Moriarty/USFW/Public Domain/Wikimedia Commons
The fungus appears to take advantage of bats' lower body temperature and slower body processes during hibernation. It does not cause much harm to some species, but to others it is extremely dangerous. In some wintering areas, 90-100% of individuals die, and in total millions of bats have died, many of which feed on pests and thus benefit agriculture. P. destructans was first discovered in the Northeast of the United States, but in subsequent years it has also been found in Canada, the Midwest, and more recently it has appeared in Oregon - on the Pacific coast of the country.
The death of North American bats is one of the most widespread among wild mammals, but even it pales in comparison with what happens to amphibians. In the 1970s and 1980s, experts studying amphibians began to notice that the animals had disappeared somewhere, although everything around looked the same. In The Sixth Extinction, Elizabeth Colbert says: "An American herpetologist went to the Monteverde Cloud Forest Reserve in Northern Costa Rica to study the reproductive behavior of orange toads. She spent two field seasons searching; where toads used to mate in hordes , she managed to spot only one male."
The causative agent was first identified only in 1998. It was an unusual chytrid fungus, which was named Batrachochytrium dendrobatidis . The fungus invades the animals' skin, interferes with their ability to absorb electrolytes, and, Colbert writes, they die of a heart attack. In 2013, another fungus that causes chytridiomycosis was discovered - B. salamandrivorans . As the name implies, it mainly affects salamanders. It is likely that both pathogens originated in Asia, from where they spread to other parts of the world.
In 2019, four dozen scientists from different countries tried to assess how chytridiomycosis has affected biodiversity. According to their calculations, due to chytrid fungi, the number of at least 501 amphibian species has decreased, and about 90 species are likely to have completely died out. The largest decline in numbers occurred back in the 1980s, since then only 12% of the populations of species have recovered to some extent, and new outbreaks of the disease are possible in the future.
Scientists called the spread of chytridiomycosis by analogy with the pandemic panzootic. Not a single disease in history has reduced biodiversity so much (a year later, another team of scientists questioned the estimates, but not the key conclusion of the work; however, the researchers stand their ground).
Why fungi are so hard to deal with
A recurring pattern in outbreaks is the introduction of a fungus or oomycete into a new environment with suitable but non-resistant hosts. This has happened throughout human history. But transcontinental transport and international trade, including illegal ones, greatly increase the risks.
Biosecurity protocols such as quarantines have been developed to prevent pathogens from entering a new location. However, there are problems with them. The case with P. destructans . Bats with white nose syndrome were first discovered in a cave popular with tourists. They may have carried fungus spores on clothing, shoes, or equipment. It is unlikely that all this could be disinfected. And it would hardly have occurred to anyone, because neither the disease nor the fungus that causes it was previously unknown (and for species that are clear that they are dangerous, there is often not enough data for accurate identification).
The amazing abilities of fungi and oomycetes make it even more difficult to fight them. Many of them can survive for a long time without a host or throw out tenacious spores. So, if you raise amphibians in captivity and release them where they disappeared from due to B. dendrobatidis , the fungus will almost certainly kill them again. Even worse, it parasitizes hundreds of species, but does not harm all: those amphibians that easily carry the infection can become "superspreaders". And it is practically impossible to clear tropical forests from B. dendrobatidis .
Orange toad. The species is considered extinct due to the fungus Batrachochytrium dendrobatidis
© U.S. Fish and Wildlife Service/Public Domain/Wikimedia Commons
Another advantage of fungi and oomycetes is genetic flexibility. They relatively easily form hybrids, receive genes through horizontal transfer (not from parents, but from other individuals, even if they are a foreign species), and “shuffle” entire DNA sections as a result of recombination. Thanks to this, they can quickly adapt to their hosts, increase virulence, acquire resistance to drugs and adverse factors. The new environment opens up new possibilities for this.
Another problem is that we still have a poor understanding of the diversity of fungi and oomycetes. Presumably, the kingdom of fungi has from 1 to 5 million species, but only about 5% of them have been described, and those that are considered to be one species by external signs sometimes differ significantly genetically. How many pathogens are among them, one can only guess.
Finally, fungal infections have not been studied in the same way. Plant diseases are better understood than animal diseases, and crop diseases better than wild species. The damage from lost crops is easier to calculate, it is easier to fight pathogens on cultivated lands than in a forest far from civilization. So, in 2018, scientists checked scientific articles on the fight against amphibian chytridiomycosis and in most of them they did not find any recommendations, and the cost of control measures was discussed in less than 1% of the articles.
It would be an understatement to say that the extinction of dozens of amphibian species, the death of billions of trees and millions of bats are alarming signs. However, it is often unclear how bad things are, what the consequences are, and what can be done. Fungi and oomycetes benefit from our confusion and will puzzle us more than once.
Eucalyptus plants of Australia. Eucalyptus tree
world - shrubs, trees and grasses of various types and different, sometimes record height. These record holders include well-known Australian eucalyptus. Without these green giants, as without kangaroos and acacias, it is impossible represent Australia. Eucalyptus - an integral constituent element rather poor forests, in some places covering this unusual mainland.
Some green giants even exceed 100 m in height, with trunks more than 30 m in girth and about 8 m thick. Just like skyscrapers, only miraculous and green. Naturally, the height of eucalyptus is different, because the number of their species exceeds 300. It's funny that the birthplace of one of the largest eucalyptus trees on the planet - this is the smallest mainland of the planet Australia. Another interesting fact is the name of this unique tree. does not correspond to reality, because "Eucalyptus" in translation from Greek means " I cover well ", which means I give good shade. In fact, the opposite is true. Eucalyptus trees give absolutely no shade, despite their dense branches and this is due to the way they are placed narrow leaves facing the sun with an edge and creating the effect of blinds. Eucalyptus trees are evergreen trees that do not shed their green cover annually, like other plants, but instead they shed bark. This usually happens in August (February in the southern hemisphere). AT at this time, the trunks of trees acquire a blue or bright yellow color and become very smooth, and later an updated bark grows on them.
Eucalyptus trees are extremely useful. They grow very fast, already in the first a year reaching 2-3 m in height, and by the age of five 12 m, while the thickness the trunk is up to 20 cm. It is during this period that they are most suitable for industrial use - the manufacture of beams and telegraph poles. Reaching the age of 20, the entire hectare of eucalyptus forest can give up to 800 cu. m of very valuable timber. None of the known wood species cannot give such an amount even in 120 years, because at 35 eucalyptus already has the parameters of a bicentennial oak.
Due to its extraordinary hardness, eucalyptus enjoys great glory. Its wood is widely used in the construction of ships, dams and a variety of structures for which the durability of materials is important. Eucalyptus wood is also used in the manufacture of furniture, railway sleepers, in the construction of houses. Eucalyptus practically does not rot, it does not contain bark beetles start up. It is very difficult to set it on fire, however, the coal obtained from eucalyptus, has no equal in its properties. Also many types eucalyptus are rich in tannins, which are used to process skin.
And that's not even all the useful properties of eucalyptus. As a rule, flowers of plants, native to Australia are odorless, but their foliage is very fragrant. Eucalyptus is no exception to this rule - its leaves contain a huge amount of the most valuable essential oil (for example, from 36 kg of foliage you can get half a liter of oil), with its smell reminiscent of lemon. Eucalyptus oil is widely used in medicine and in the manufacture of cosmetics. products - soaps, varnishes, colognes, etc.
Eucalyptus trees need moist soil, which is why they grow mainly near rivers, lakes or the sea coast.
The most valuable of the properties of this tree is its striking ability to the drainage of the soil, due to which the eucalyptus is called the "tree-pump". The widely developed root system of eucalyptus pulls a large amount of water out of the ground. the amount of moisture subsequently evaporated through the foliage. This is another paradox of eucalyptus - the most moisture-loving tree on the planet grows on the driest of its continents. It is estimated that only one hectare eucalyptus forest evaporates about 12 million liters of water per year, and this over a million buckets. For this reason, under the shade of eucalyptus trees, not a single plant survive. As natural pumps, eucalyptus trees are very quickly drain the surrounding area, and at the same time reduce the amount malarial mosquitoes. That is why eucalyptus in huge quantities planted in countries with high humidity, located in different parts of the world. Many of these trees are also planted in the swamps of Colchis in Georgia. Where not so long ago a human foot has set foot, grow dense eucalyptus forests. Eucalyptus swallowed up not only quicksands, but also destroyed the malarial mosquitoes that plagued Western Transcaucasia. Today, the drained lands of the humid subtropics, which turned out to be extremely fertile, used to grow many valuable crops subtropics.
The history of the common specific name of green giants is very interesting. They were first called California Pines or mammoth trees , because the ends of the branches of these trees, bent upwards, very reminiscent of mammoth tusks. Choosing a scientific name this tree, the Swedish botanist Carl Linnaeus, who studied sequoia in 1859, gave her the name of the English commander Wellington, naming the tree "Giant Wellingtonia". True, this name has existed not so long - outraged Americans quickly renamed the tree and named him after national hero George Washington. So Wellingtonia became Washington. To streamline the diversity of names, scientists came to compromise solution - to call the tree the same as the Indians called it - sequoia. Then they did not know that this name belonged to one of the leaders Iroquois, who led the liberation struggle of the Indians against the colonialists. It turns out that the tree did not receive the name of an Englishman or an American - in It immortalized the memory of an Indian folk hero. True enough the old name of the sequoia is often used - "mammoth tree".
In 1857, sequoia was planted in the Crimea, in the Nikitsky Botanical Garden, where now it surprises visitors with its impressive dimensions. In general more than 100 sequoias grow on the territory of the southern coast of Crimea.
North American conifer giants, redwoods, are not inferior in height Australian eucalyptus. The highest specimens also reach more 100 m, while their trunks are much thicker. So, for example, one of sequoia known to science in girth was 46 m, and in diameter 15 m.
Sequoias are real "living fossils". These trees were common in the Ice Age throughout the Northern Hemisphere, as well as in the southern regions of Eastern Europe. Just imagine how these trees roamed huge lizards - brontosaurs and dinosaurs, and their branches were used for rest by pterodactyls, the ancestors of modern birds.
To our time, sequoias in the wild have survived on the planet only in the US state of California, and grow only on the western slopes Sierra Nevada. The average age of trees, like eucalyptus trees, is 3-4 thousand years, and thanks to the calculations of annual rings visible on the stump one of the felled trees showed a record age for a tree - 4830 years! By the way, cutting down such a tree is extremely difficult. One of the redwoods I had to cut with a seven-meter saw for 17 days, and for its transportation it took 30 large railway platforms.
Science knows cases in which on the stump of a giant felled sequoia there was a dance floor, on which not only an orchestra consisting of 4 people, but also 16 dancing couples and even 12 spectators.
In some cases, souvenir shops were placed in the hollows of the sequoia, moreover, in one of the hollows, the craftsman equipped a garage. In one of the New York museum exhibits a part of the trunk of a huge sequoia cut down in California. The tree has a girth of 75 m. Inside it was equipped with a hall, which can easily accommodate about 150 people.
Sequoia wood, unlike eucalyptus, is light, but it also does not rot and was previously widely used in construction, which became cause the complete annihilation of this incredible tree. Small these days the number of surviving giants is protected by law - they grow in the reserves. In such reserves, each of the trees has its own name. The largest sequoia was named "Founder" (112 m height). They also live here as "Pride of the Forest", "General Sherman", "Abraham Lincoln" and many others.
In our article you will find information about the appearance of eucalyptus, as well as find out in what areas of life it can be used by an ordinary person.
On our planet there is a huge number of different trees, which are quite impressive in size. But, perhaps, eucalyptus stands out most of all against the background of the rest. The main feature of this tree is that, with a very large crown, it practically does not give shade.
This is due to the fact that its leaves are always located edge to the sun. Such an interesting feature allows eucalyptus to retain accumulated moisture for a longer time and calmly wait out dry periods.
Eucalyptus - tree: types, how it looks, how it blooms: photo
Eucalyptus is a member of the myrtle family. Scientists call plants of this species natural pumps because they can suck up from 150 to 250 liters of fluid from the ground in one day. An adult healthy tree passes through about 100 tons of water per year. Eucalyptus is an evergreen tree whose trunk is covered with easily detachable bark. As for the leaves, their shape may change as the tree grows.
In young plants they are round and slightly bluish in color. But the older the tree gets, the longer and greener the leaves become. Approximately in the fourth year of life, they acquire their elongated shape and no longer change it.
Eucalyptus also blooms differently from other plants. First, in place of the future flower, a soft-to-touch box is formed, with a bottom, which for some time increases in size and becomes stiff. As soon as this happens, the bottom falls off, the box opens and a fierce brush of hair stamens appears from it. This is the eucalyptus flower. Depending on the type of plant, it can be pink, yellow, white or red.
Homeland of eucalyptus, where does it grow?
Homeland of eucalyptus
Australia and Tasmania are considered to be the homeland of the eucalyptus. About 500 species of this green giant can be found in these territories. In Australia, the eucalyptus, in general, is a forest-forming tree that grows everywhere. Since it is considered a natural pump, it can be found not only in wild forests, but also on the territory of private farms. These green giants carry out natural land reclamation and people do not have to spend extra money on it.
In addition, eucalyptus can be found in Africa, India and even France. True, low-growing species of this plant grow in these countries, which need a minimum supply of moisture. They also tried to grow eucalyptus in our country, but because of the unsuitable climate, it does not grow well here. But still, some varieties were able to adapt to our weather conditions, although they can only be seen on the Black Sea coast, for example, in Sochi.
Eucalyptus - giant tree: trunk height, tallest eucalyptus
As you already understood, eucalyptus belongs to giant trees that have a height of more than 70 meters. In a suitable climate, this tree quite easily grows to a height of up to 100 meters and has a trunk width at the base of 15 to 30 meters. True, in order for the eucalyptus to grow to such a size, it needs ideal climatic conditions, high humidity and a sufficient amount of ultraviolet radiation. Therefore, such giants can only be found in the natural tropics. That is why less tall eucalyptus trees are found in the more familiar climate zone.
As a rule, they have a height of 40-60 meters and a trunk width of no more than 10 meters. At the moment, the tallest deciduous eucalyptus in the world is considered to be a giant that grows in the wild forests of Tasmania. Scientists have found that its dimensions already now reach 101 meters in height and 40 meters in width. The uniqueness of this specimen is also in the fact that it is the largest flowering tree on the planet.
Which tree is taller chestnut, giant eucalyptus or sequoia?
Eucalyptus and sequoia - green skyscrapers.
Although the eucalyptus is considered a green giant, it still has rivals who, under favorable conditions, can significantly overtake it in growth. Such a tree is considered an evergreen sequoia, belonging to the genus of conifers. Under favorable conditions, this tree will quietly grow to a height of at least 110 meters. In 2006, scientists found on one of the slopes of the Sierra Nevada mountains a sequoia more than 115 meters high and with a trunk width of more than 11 meters, and for more than 10 years the title of the most giant tree on the planet has officially belonged to her. Scientists do not disclose the exact location of this unique specimen, as they are afraid that crowds of tourists will simply destroy the powerful natural giant.
That is why only photographs of the tree were provided to the public, and only a very narrow circle of people knows the exact coordinates of the growth of the sequoia. As for the chestnut, it can also be called a high-growing tree, although compared to eucalyptus and sequoia, it will still look like a baby. Even in the wild, this tree does not grow more than 35 meters in height, so for us it may seem like a fairly tall specimen, but for people living in Australia or Africa, the chestnut tree will be quite an ordinary deciduous tree.
How long does a eucalyptus live?
Eucalyptus lives from 300 to 500 years
Eucalyptus is a tree that can live quite calmly for at least 500 years, although for this it needs the most favorable conditions. If it receives the right amount of moisture and light, then in a hundred years its height will reach 100 meters.
But since at the moment we have quite big environmental problems that greatly affect the climate, even in the tropical climate zone, the life expectancy of eucalyptus trees has been reduced to 400 years.
How does eucalyptus reproduce?
- Eucalyptus is a cross-pollinated plant in which the male and female flowers are on different trees. Therefore, in order for pollination to occur, it is necessary for pollen from one eucalyptus to fall on another. It helps to make rain, wind and insects. After the flower is pollinated, it forms a seed pod, which after a while opens and throws the seeds to the ground. Once in the soil, they just lie in it for a couple of days and gain moisture.
- As soon as there is enough moisture, the change begins to take root and if everything goes well, then after a while a young shoot of eucalyptus appears from the ground. But this is how reproduction occurs only in nature. If a person is engaged in propagation of eucalyptus, then he only needs to purchase seeds in a specialized store and sow them in a container with a good drainage system, which will constantly saturate the soil with the right amount of moisture. After the seeds are lowered into the soil, they will need to be covered with plastic wrap and put to warm up in the sun.
- It will help keep you warm and create the sort of greenhouse effect that eucalyptus trees need to grow as fast as possible. Also, if you wish, you can try to propagate this tree with cuttings. To do this, you will need to get a small, preferably healthy cutting, hold it in a disinfectant solution, and then plant it in a soil rich in nutrients.
How and why does eucalyptus shed its bark?
Eucalyptus is such a unique plant that it does not even regenerate like other deciduous trees. Unlike his relatives, he sheds bark instead of leaves. It is precisely because in the process of updating the eucalyptus that the trunk is completely exposed, it is also called "shameless". The most intense tree sheds bark in the tenth year of life. For the first nine years, the eucalyptus grows in height, but when it reaches the age of 10, growth stops a little and the trunk begins to grow more intensively.
At this time, the wood grows at a fairly rapid pace, and since the bark does not keep up with this process, then at a certain period it simply begins to move away from the trunk. Sometimes this happens very quickly, and sometimes the bark just becomes softer and hangs on the tree in tatters for a while. As soon as all the bark leaves, a new smooth layer begins to appear on the trunk, which subsequently also becomes stiff and falls off.
Who eats eucalyptus?
Eucalyptus leaves are a favorite food of koalas
Eucalyptus leaves are food for koalas, who live exclusively on these trees. Previously, it was believed that these animals feed on eucalyptus leaves only because they are a source of a huge amount of moisture. But modern scientists have dispelled this myth and proved that koalas, although very rarely, still drink ordinary water.
At the moment, such an addiction to the leaves of this tree is explained by the fact that at a height they are well protected from aggressive predators that threaten them on the ground. Since they are very slow, they live, eat, move and breed on the branches of the eucalyptus, and only in the most extreme cases descend to the ground.
Mushroom growing next to eucalyptus: name
Mushroom growing next to eucalyptus
Eucalyptus groves are an ideal breeding ground for such an exotic fungus as the truffle. Its mycelium wraps the root system of the tree very tightly, sometimes even partially penetrates into it, and helps it absorb water more quickly. And the tree, in turn, gives the mushrooms some of its nutrients. Such a symbiosis helps both the eucalyptus itself and the fungi to develop well.
This peculiar truffle, like its direct relatives, grows underground. Therefore, if you want to find a mushroom in a eucalyptus forest, then you will need to carefully dig the soil around the tree. As practice shows, most often the fruit bodies of truffles are at a depth of 20 cm.
How do eucalyptus trees help fight malaria?
Eucalyptus in the fight against malaria
As mentioned at the beginning of our article, one adult eucalyptus drinks as much water per day as several undersized trees. That is why it is very often planted in wetlands, which are the habitat of malaria mosquitoes. Gradually, they dry out the top layer of soil, thereby taking away from them the opportunity to fully reproduce. As soon as the soil becomes low-moisture, mosquito larvae begin to die and after a while they themselves disappear.
True, adults are not afraid of the lack of moisture, but the unpleasant smell emitted by eucalyptus leaves. They contain strong-smelling essential oils, which are very much disliked by malarial mosquitoes. Therefore, if you plan to relax in a country where there is a risk of contracting malaria, then take natural eucalyptus oil with you and apply it on your hands, feet and earlobes before leaving the hotel. Such measures will be quite enough to ensure that malaria mosquitoes do not come very close to you.
Benefits and harms of eucalyptus, where is it used?
Benefits and harms of eucalyptus
Eucalyptus leaves, roots and bark contain a huge amount of substances useful for the human body. That is why people very often use them to prepare folk remedies intended for the treatment of certain diseases. Also, on their basis, various care products for the skin, hands, hair and nails are prepared.
Eucalyptus is used to treat:
- Infectious diseases
- Runny nose
- Immunity enhancers
- Pustular processes on the skin
- Effectively and permanently purifies the air in your home
- Beneficial effect on the respiratory system
- Helps the circulatory system to oxygenate more quickly
- Improves blood circulation in the upper layers of the skin
- Improves carbohydrate metabolism
- Helps fight migraine pain
- Relieves swelling of limbs
- Perfectly freshens breath
- Increases endurance
- May cause an allergic reaction
- With prolonged use, an excess of certain substances in the body may be observed
- Promotes high blood pressure in hypertensive patients
- May cause slight irritation to skin and mucous membranes
What is made from eucalyptus: bath brooms, blankets, pillows
Eucalyptus pillows and blankets
If earlier only essential oil was made from eucalyptus, now, thanks to scientific progress, mankind has learned to use all parts of this unique natural giant for its needs. Recently, people began to process eucalyptus wood with a special chemical composition. He softens it and turns it into a fairly flexible and smooth yarn, which is used to make filler for pillows and clothes.
Such a filler is considered environmentally friendly, so both asthmatics and allergy sufferers can safely buy such products. Another popular eucalyptus product is bath brooms. They are made from young and flexible branches that have the strongest aroma. The use of such a broom in a steam room or sauna helps to normalize the respiratory system, and also contributes to the fact that all regeneration processes in the skin are enhanced, as a result of which wounds and cracks heal much faster.
Eucalyptus ( Eucalyptus ) belongs to the myrtle family. These are evergreen, rarely deciduous, fast-growing large trees and shrubs. The trunk is covered with easily separated bark.
As you can see in the photo, the leaves of eucalyptus are simple, entire, arranged depending on the age of the plant:
In young trees, the leaves are opposite and sessile, in adults, alternate, lanceolate, oblong, rounded, hard, green, gray, in numerous glands containing essential oil.
Pay attention to the photo - eucalyptus flowers are collected in 10-12 pieces, have a nondescript corolla, but a large number of bright stamens:
Eucalypts are evergreens, but instead of leaves they can change the top layer of the bark, which turns into tatters and falls off.
There are over 500 species in the genus. The homeland of eucalyptus trees is Australia, where they are extremely diverse: they are mostly trees, but there are also shrubs.
These plants are distributed not only in Australia, but also in the Malay Archipelago, New Guinea and the Philippine Islands. "They cause a cry of admiration!" - such a description of the eucalyptus tree was given by Jules Verne.
These photos show what eucalyptus looks like in the wild:
The name "eucalyptus" comes from two Greek words - "beautiful" and "closed". The latter, apparently, is associated with the special shape of eucalyptus buds, as if closed with caps.
This plant was first brought to Russia by the founder of the Batumi Botanical Garden, AN Krasnov, in the early 80s of the 19th century. It took almost 50 years to introduce eucalyptus into cultivation.
Now these plants grow in our country mainly on the Black Sea coast of the Caucasus, less often in other regions of the Caucasus, Crimea and Central Asia.
Look at the photo of how eucalyptus blooms in natural habitat:
In medicine, leaves of only three types of eucalyptus are allowed for use: ball, ashen and rod-shaped.
Growing eucalyptus from seeds at home (with photo)
Eucalyptus can be grown indoors, but only from seeds, because adult plants almost never appear on sale. Eucalyptus seeds are very small, they are sown in bowls on the surface of a moistened mixture of light humus earth with sand and slightly pressed. The first 3-4 days you should not water the seeds.
When growing eucalyptus from seeds at home, shoots appear in 5-10 days. Young eucalyptus seedlings require a lot of light and clean air, do not tolerate excessive moisture. When 4 leaves appear on the shoots, they are carefully transplanted into pots without damaging the roots. After planting, they are watered, then they are not watered for 3-4 days, and then regular watering is needed so that the earth is moist (but not wet).
Three to four weeks after planting, the plant can be placed in its permanent location. Eucalyptus trees need direct sun, they are grown on the southern windows. Usually seeds are sold from relatively stunted eucalyptus species, but it is likely that after 5-6 years the tree will rest on the top of the ceiling, and it will be necessary to replace it with a new seedling.
Propagation of eucalyptus by cuttings and care at home
Eucalyptus is also propagated by cuttings. To do this, a cutting 8 cm long is cut off and planted in a small pot with a light earthen mixture. When propagating eucalyptus, the stalk is covered with a transparent bag and cleaned in a warm place. With the appearance of the first leaves, the package is removed and the plants are allowed to acclimatize.
The rooted cuttings can then be planted several times in large pots. After a few weeks, pinch the tops of young shoots.
These plants are real "pumps", they consume a lot of water, and you need to make sure that the soil does not dry out. However, in winter, care should be taken in watering, avoiding waterlogging. In winter, the air temperature should not be below 7-12 degrees C.
This is a heat-loving plant, so you need to create appropriate growing conditions for eucalyptus: in summer, keep it at an air temperature of 15-18 degrees C. It should be placed in bright rooms, not allowing direct sunlight. Eucalyptus grows and develops slowly, blooms throughout the summer.
When caring for indoor eucalyptus at home, young plants should be transplanted once a year, older ones after 2-3 years. In the spring-summer period, it needs top dressing with mineral and organic fertilizers 2-3 times a month. The rest of the time it does without top dressing.
Pay attention to the photo - a houseplant eucalyptus in spring needs pruning:
Ball Eucalyptus: photo and cultivation of a houseplant
Eucalyptus ball ( Eucalyptus globulus Labill ) is an evergreen tree, up to 50–70 m high, the tallest tree in the world (found up to 155 m), very fast growing, from the myrtle family. The root system is powerful, the wood is strong. The bark of the trunk and branches is smooth, whitish-gray in color, the outer layer exfoliates.
Tasmanian Blue Gum - Tasmanian blue gum (resinous) tree, Southern Blue Gum - southern blue gum tree, Blue Gum - blue gum tree.
Popular names indicate the bluish color of the bark and the presence of gum and resins in the tree.
As you can see in the photo, the young shoots of the ball eucalyptus are tetrahedral, covered, like the leaves, with a bluish waxy coating:
Leaves of young plants and young shoots sessile, opposite, ovate or broadly lanceolate. The leaves of old plants are dark green, wider and longer, alternate, short-petiolate, entire, drooping, dense. The pulp of the leaves, in receptacles, contains essential oil.
Pay attention to the photo - the eucalyptus tree of this species has large, single, axillary flowers, sessile on a short pedicel, the buds are tightly closed with caps that fall off when the flower blooms:
The essential oil gives the leaves a sharp specific smell. Blooms in autumn, in the 3rd year of life.
Eucalyptus bulbus is grown in direct sunlight, young plants on windows with southern exposure. When they become adults, they are placed near the same windows.
The optimum temperature for growth and development is +2026 °C. In winter, it can be grown at a lower temperature of +10–14 °C, although it has a rather high frost resistance and can tolerate short-term frosts down to -10 °C without significant damage.
Seeds are sown in January-February, almost superficially, only lightly covered with earth (1–2 mm). Before sowing, the soil is well shed. Seedlings appear at a temperature of +18-20 ° C in 7-10 days. Already one-year-old seedlings, when sown in early spring and with good care, can reach a height of 1 m or even higher.
During the period of active growth, from March to September, regular abundant watering is carried out, in autumn and winter watering is limited, but the drying of the earth should not be allowed.
During intensive vegetation, in the spring and summer, fertilizing with full mineral and organic fertilizers is carried out once a month.
After weaving the clod of earth, in the spring, plants are transplanted; young plants - annually, adults - once every 4–5 years, however, it is necessary to annually add fresh soil.
Rarely affected by pests and diseases indoors. The death of plants is possible even with a slight drying of the clod of earth.
In the photo of eucalyptus at home, you can see how the trees look after planting and upon reaching 4-5 years of age:
Ashen and rod-shaped eucalyptus: photo and description
Here you can find photos and names of other species of eucalyptus found in the wild and culture.
Ash eucalyptus ( Eucalyptus cinerea ) have other names: Argyle apple - Argyle apple, Mealy Stringybark - mealy fibrous bark.
The description of the ashen eucalyptus is similar to other representatives of the species, but it also has a number of differences. Tree up to 25 m high, trunk diameter up to 70 cm. The bark on the trunk and on large branches is coarse-fibred, reddish-brown; on small and terminal branches, the bark is smooth, creamy white, falling in small strips. The leaves are bright gray, arranged oppositely; juvenile leaves in a large number of pairs, sessile or on short petioles, up to 4.5 cm long and up to 5.5 cm wide, ovate, rounded, heart-shaped or heart-lanceolate; adult leaves are sessile or short-petiolate, similar to juvenile leaves, sometimes lanceolate and then 10–13 cm long and 2.5–3 cm wide.
Grows along river banks in southeastern Australia. Blooms in autumn and winter (October-March).
Eucalyptus ( Eucalyptus viminalis Labill ) - a tree up to 50 m high and a trunk diameter up to 1. 1 m. The bark is smooth, white, falling or rough, scaly, at the base of the trunk, sometimes there are trees with more or less deeply furrowed bark to the upper branches. For him, as for all species of the genus, heterophylly is characteristic, i.e., diversity (juvenile-young and adult leaves have a different arrangement, shape and size). Juvenile leaves are opposite, in a large number of pairs, sessile or amplexicaul, narrow or broadly lanceolate, up to 10 cm long and up to 3 cm wide, dark or light green, shiny. Transitional and adult leaves grow spirally, the first ones are petiolate, broadly lanceolate or lanceolate-pointed, up to 27 cm long and 4–5 cm wide, pale or dark green, flat or wavy, the second ones are petiolate, lanceolate, often sickle-shaped, 18–24 cm long and 1.5–3 cm wide, pale green, flat or wavy. The flowers are small, collected in axillary three-flowered umbrellas.
Manna Gum - semolina gum (resinous) tree, White Gum - white gum (resinous) tree, Ribbon Gum - ribbon gum tree, Viminalis - rod-shaped.
Common names indicate the presence of a large amount of gums in this eucalyptus, as well as the white color of the bark.
Blossoms in summer, July-August, some trees in winter and spring (December-May).
Crosses easily with other species. Occurs on plateaus along rivers, along mountain slopes, coasts of southeastern and southern Australia and Tasmania.
First cultivated on the Black Sea coast in 1882.
Since childhood, people know that the eucalyptus is the largest tree in the world. However, there are more than a dozen varieties of it, and only the regal one differs in such impressive sizes. The rest have much more modest parameters, although they still cannot be called miniature. Some species are widely represented in greenhouses and botanical gardens - eucalyptus flowers, and any, are very attractive and unusual. For amateur gardens, the plant is not very suitable, because it is still tropical and requires the maintenance of specific conditions. However, for indoor crop production, some species are still suitable. And they can often be found in apartments. The reason for acquiring and growing a tree is again eucalyptus flowers, which will decorate and diversify a home garden. True, it is not always possible to achieve such beauty from a plant, but there are still chances.
What is a eucalyptus flower? While the bud is ripening, it is covered, like a cap, with lignified petals fused into a single whole. A kind of panicle of long and thin stamens is hidden under this cover. When ripe, eucalyptus flowers take off their cap and reveal to the world a whole lush mane of different shades - pink, yellow, white, fiery red. Actually, because of such an unusual flowering, the tree got its name: in Greek, “eu” means “beautiful”, and “calyptos” means “closed”, “closed”.
All eucalyptus species are native to Australia or Tasmania. All plants are similar: the shape of the crown is pyramidal, the leaves are greenish-gray, giving the impression of having a light coating. Interestingly, the foliage changes color and shape as it matures. Eucalyptus flower, fading, forms a box with seeds.
Among the species that can be cultivated at home, there are three varieties worth mentioning:
The principles of cultivation are approximately the same, although external differences are observed in them.
This species is native to Tasmania. In the wild, it grows up to thirty meters, at home - no higher than one and a half meters. At a young age, the tree has heart-shaped rounded bluish leaves up to four centimeters in length; in an adult - lanceolate, narrow, up to seven centimeters, densely green. Speaking about the eucalyptus flower (photo above), it should be noted that its peduncle is flattened, and the flower bud is club-shaped. The fruits do not look like a box, but like a bell.
It is native to Australia. There, a tree can grow up to 20 meters; when grown indoors, it usually does not reach above a meter and a quarter. Its leaves are longer, up to 15 centimeters, and narrow, with a distinct lemon flavor.
In its homeland it is a tall, strongly branched tree. In indoor growing conditions, it is a relatively low bush that needs to be systematically pinched and trimmed. In youth, the leaves are lanceolate, wide, with a wavy beautiful edge. In an adult tree, they bend like a sickle, stretch out and begin to resemble willow leaves. The bark of the globular eucalyptus rejuvenates every year, peeling off in patches, under which a new cover is formed. The fruits that produce eucalyptus flowers of this variety have a spherical shape and ripen for a very long time - up to two years.
Light and temperature
None of the eucalyptus species require special tropical conditions. In summer, 24 degrees during the day and 18 degrees at night are enough for him. In winter - about 15. It is perfectly acceptable to move the pots on. As for the light, the plant likes direct rays. West and southeast windows will suit him perfectly.
Watering and fertilizing
Sufficient water supply from spring to autumn. The frequency of watering - how the top layer of soil dries up, to a depth of a third of the pot. In winter, watering is more rare: after the specified volume has dried, they wait another half a week. Eucalyptus do not need moisturizing, they do not require spraying.
In eucalyptus, once every two weeks, it is fed with complex universal fertilizers. During the dormant period (starting in September), feeding is stopped.
Features of growth
It is worth considering that all eucalyptus trees are fast-growing plants. Despite the fact that in room conditions their development slows down somewhat, the pace remains impressive. However, at first, the tree has only a very thin, brittle twig.