The Big, Bad Book of Botany
Page 2
Behind the Sprouts
Alfalfa is a perennial and can live in the wild for twenty years and grow to about 3 feet in height. In the last few decades, many people have touted the nutritional value of eating alfalfa sprouts, which continues to reign as one of the totems of “health food.” Many of the commercially grown alfalfa crops have been genetically modified, however. In 2005, scientists managed to splice the genes of certain alfalfa plants with a chemical compound found in the weed killer known especially under the brand name Roundup. This allows farmers to spray herbicide to kill surrounding weeds without affecting the crop. While alfalfa seeds and sprouts do contain proteins, amino acids, and vitamin D, in some cases they can cause people to develop a disease similar to lupus if consumed in excess. The best alfalfa sprouts to eat are those of the unmodified stock, germinated in only purified water.
ALOE VERA
Aloe barbadensis
Medicine in a Leaf
The succulent aloe vera plant that we know today is a derivative of a wild species now extinct. What grows today is a product of four thousand or more years of cultivation. We know this from numerous medical texts that specifically mention the plant for its multiple health benefits. Egyptian papyruses dated to 2000 B.C. contain formulas for aloe vera’s use as a remedy for any number of external and internal aliments. Alexander the Great supposedly made sure to conquer the small island of Socotra for its abundant crops of aloe vera, which he needed to heal the wounds of his soldiers. So essential was aloe to medicine, Western explorers nearly always took it with them, beginning in the 1500s and throughout the era of colonization, spreading it around the globe. Since its leaves can be stuck in soil and will easily take root on their own, aloe vera grows outdoors in temperate and tropical climates throughout the world, from the Caribbean islands and the Indian countryside, to gardens in Australia and the windowsills of many urban apartments.
Aloe is a large group, with more than 500 varieties, all of which have fleshy leaves for storing water and nutrients. The aloe group traces its territorial origins to Africa and the Arabian Peninsula. There are many succulents—12,000 different species—and the group evolved rapidly, appearing first in the late Paleocene and early Eocene climatological epochs of about fifty-five to fifty million years ago. The period was marked by dramatic warming, such that tropical alligators, for example, could live in regions of what we now call Greenland. Numerous plants went extinct but those that did survive the epochs’ haphazard shifts from abundant rain to prolonged months of drought really thrived. To achieve this feat, however, these succulents had to practically reinvent the biological systems plants had employed for countless eons. Instead of growing roots deeper into the soil to search for water, the succulents went up, making their leaves their canteens and storehouses.
Succulent comes from the Latin word succos, meaning “juice.” The waxy leaves of succulents developed what are called stomata, or surface pores, which help reduce water loss. Opposite to how they work in deciduous leaves, in succulents these pores close during the day and open up at night. In simpler terms, succulents began working the night shift to capture needed carbon dioxide, using the cooler temperatures to prevent too much water from escaping. The plant stores the essential gas until the following day, when it’s combined with sunlight and water to create carbohydrates and sugars.
Medical studies over the last fifty years have regularly attested to aloe vera’s ability to aid in healing wounds, impeding skin fungal growth, reducing inflammation, and even correcting the side effects of hypoglycemia, some gastrointestinal ailments, and certain types of diabetes. It all comes down to the predominant type of chemical found in the plant, classified as polysaccharides. Many plants have these complex carbohydrates. Even though aloe’s pulp is nearly 99 percent water, aloe contains in its other 1 percent a special blend of enzymes, minerals, water-soluble and fat-soluble vitamins, polysaccharides, and organic acids. The chemicals found in this small percentage of the plant’s makeup are diverse and wide-ranging. They include enzymes such as alkaline phosphatase, inorganic compounds such as calcium, chlorine, chromium, and zinc, and amino acids, including leucine and lysine, to name but a few, as well as vitamins B1, B2, B6, C, and folic acid. Aloe vera’s medicinal formula is one that only nature’s grandest chemist could have devised.
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More than three hundred pharmaceutical drugs now in use mimic the chemical composition of certain plants long known to possess healing properties. Aloe products have spawned a multibillion-dollar industry that employs the plants’ “juices” in numerous first aid products and skin care lotions.
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ANGEL TRUMPET
Brugmansia sauveolens
Temptress in D Flat
Beauty is often deceptive, and sometimes the prettiest things prove the most deadly. The angel trumpet is one such tropical, exotic plant. It blooms with gorgeous, dangling flowers shaped like a horn—such as the trumpet—in vibrant shades ranging from yellow, white, pink, and orange to cream. It likes hot weather, 80 degrees or more, and cool nights. It is an annual plant, its life span roughly only one season long. But in that short time, the angel trumpet can grow into a woody, stalky shrub with a height of nearly 6 feet and a girth of 20 yards. A shrub can produce hundreds of dangling flowers, each as beautiful as the next. Though a native of the tropics, it’s planted during the summer in northern climates as a border shrub, often used to define landscaping perimeters. Many herbivores, such as deer, somehow can detect that the plants are poisonous and know not to eat them. Hummingbirds particularly enjoy angel trumpet nectar, and the plant is adept at attracting a wide array of pollinators, such as honeybees and other insects.
The scientific name of the angel trumpet is Brugmansia, and it belongs to a genus of only seven similar flowering plants grouped in the Solanaceae family. Most of the shrubs in this family contain strong and highly toxic alkaloids. Brugsmania is one plant that decided it was better off not relying on other organisms for propagation, instead producing bright flowers to attract the much gentler insect world to ensure pollination and survival. All parts of the angel trumpet, from the roots, stalks, stems, and leaves to the flowers, are extremely poisonous. As a result, even planting the angel trumpet is illegal in some communities.
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Paths of Survival
Paleobotany is the study of prehistoric plants and, just as is the case for dinosaur hunters and paleontologists, most of what we know of what plants were like and how they evolved we’ve surmised piecemeal; understanding what life was truly like on earth in the distant past is a jigsaw puzzle without a guide, and one with countless pieces of information to fit in place. Nevertheless, the consensus is that the first land plants appeared an incredibly long time ago, about 450 million years. It took another 250 million years before the first flower bloomed, during the Triassic period. Angiosperms, or flowering plants as we know them, came into wider disbursement approximately a hundred million years ago. This event was a major contribution to the development of terrestrial animal life; flowering plants, of course, were crucial to the evolutionary rise of insects, which in turn created a food chain allowing larger animals to evolve. Some plants adapted to find a useful way to employ the services of insects and animals, while others developed drastic means to dissuade animals from causing them harm. The angel trumpet is an example of the latter. With such attractive flowers and a short life span, the angel trumpet had no choice but to turn its entire cellular composition into a toxin deadly to any animal that tried to nibble it.
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ANT PLANT
Acacia
If You Can’t Beat ’em, Join ’em
The ant plant, one of 100 genera of plants known as myrmecophytes, has adapted to allow entire colonies of ants to inhabit it, and both plant and ant coexist beneficially from the arrangement. The plant went the bed-and-breakfast route to ensure protection from other insects, fungi, parasites, hungry herbivores, and even encroaching vines, making itself so
inviting to its guests, they would never check out. Voracious and territorial denizens, the ants never want to leave, and thus they retain a vested interest in the plants’ survival. The plants count on the ants not only for protection, but for housekeeping and pollination. In return, the ants have a ready-made colony, which provides irresistible food sources and even specialized plant secretions that stimulate better ant communication via the ants’ pheromones. Ants are so numerous on the planet, estimated to account for nearly 15 percent of the entire animal biomass, that it was a smart evolutionary move by the plant to utilize the services of these widespread and powerful little creatures, rather than wasting energy fighting them off.
The distinctive feature of these ant plants is their internal composition, with inviting hollow or tubular spaces in their swollen stems, leaves, and spines. The nectar of the plant’s flowers feeds the ants. Other types produce special buds, high in fat and protein, as a means of enticement. In general, while ants are not considered the best pollinators, since they clean themselves frequently or dust off the pollen, in this case, while gathering and feeding on the nectar of the plant, they are able to do the job efficiently. In addition, the ants then take the plant’s seeds into the colonies—within the plant itself, which serves an almost womblike function—until the seeds mature. The ants eat only the outer crust of the seed, doing no other damage to it, and then remove it from the colony and plant or disperse it. What guests!
There are 100 or more variations of ant plants, some only growing above altitudes of 3,000 feet, others finding homes in grassy areas and swamplands. In any case, in addition to its ingenious method of survival, the ant plant surely offers a lesson on the concept of peaceful coexistence between the unlikeliest of partners.
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In science, this type of union is called obligate mutualism, meaning that both species, as different as they may be, need each other for survival. In laboratory tests, when worker ants were removed from the colony of ant plants, they could find no other way to live, and so died. Likewise, the plants quickly succumbed to an array of harmful parasites and diseases.
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ARTICHOKE
Cynara scolymus
A Thorny Delicacy
There are as many as 140 different types of artichokes, all belonging to a group of plants known as flowering thistles, though about only 40 varieties are now grown commercially today. All thistle plants have spiky leaves and thorny stems, some as sharp as barbed wire, and nearly all are tailored to dissuade herbivores. The artichoke and other thistles are cataloged in the Asteraceae family, which contains 23,000 species, including daisies and sunflowers. The artichoke is native to North Africa and the Mediterranean regions, and still grows wild there. The ancient Greeks treated it as a good food source and the Romans cultivated it both as a delicacy and an aphrodisiac. In Greece, if a woman wished to bear a boy, she was told to eat a steady supply of the vegetable.
Although some recipes utilize artichoke leaves, the most edible portions are the parts of its annual bud. The bulbous bud has clusters of thick petals that, if not harvested, produce a purplish flower. The plant is a perennial, although usually it produces the edible bud only after the second year, dying off altogether after seven or eight years. It grows to about 4 to 6 feet in height, with the bud perched at the tip of its stem, which rises on a hefty stalk above its thorn-riddled leaves.
Today, California cultivates all the artichokes consumed in the United States, while the rest of the world’s supply comes from Spain, France, and Italy. As for the plant’s aphrodisiac properties, the ancient Romans weren’t entirely wrong. If you come across an artichoke that hasn’t been soaked with insecticide, the buds will contain more antioxidants than any other vegetable, which can make people who eat them healthy and possibly more vibrant. Some studies have found that the plant aids in digestion, and some have made the claim it can reduce the risk of coronary disease.
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The Fate of a Mistress
Greek mythology explains how the artichoke came to be. One day Zeus came down to earth to speak with his brother Poseidon, God of the Sea, when Zeus spotted a very attractive young woman by the name of Cynara near the shoreline. He was surprised the girl seemed unafraid and slightly aloof at meeting a god. This apparently stirred Zeus’s interest in the woman even more, and he invited her to come with him up to Olympus. Their secret affair became a regular thing whenever Zeus’s wife, Hera, was out of town, and Zeus became so pleased with Cynara that he transformed her into a goddess. Cynara got so fed up with getting attention only when Hera was out of sight that she went back down to earth to see her mother. When she returned to Olympus and Zeus learned of her unauthorized visit among the mortals, he became so enraged that he cast her out of the heavens forever and transformed her into a thistly artichoke plant.
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AVOCADO
Persea americana
A Pit for a Sloth
That slice of avocado in your salad is not a vegetable, but actually a berry.
The fruit of the avocado tree, or alligator pear (nicknamed as such for the fruit’s leathery skin), houses a huge, single pit or seed. The most familiar type of avocado plant we know today is a very ancient tree species, having originated in Mexico about ten million years ago. Cave drawings in Coxcatlán, Mexico, from ten thousand years ago that display an image of an avocado, along with fossil evidence, prove it was an important food source among aborigines.
Avocado trees can grow to 60 feet in height, with a wide outshoot of branches. The tree itself belongs to an even older family of plants known as Lauraceae, or the laurel family, consisting of as many as 3,000 different species. These plants originated when the supercontinent Gondwana comprised nearly half of the Southern Hemisphere. As the landmass shifted and eventually became today’s South America, Africa, and Australia, varieties of avocado-like plants moved with it, and as a result now appear in far-reaching semitropical climates around the world.
Self-Sufficiency
Many of the avocado’s characteristics contain hints of how ancient plants lived during that period. Avocados are evergreen; they may lose leaves, but newer ones replace the fallen leaves immediately. It is also a flowering plant, although the yellow-greenish blossoms are small at only about ¼ inch. Unlike most flowering plants, which need to pollinate (that is, transport pollen from a male flower to a female bloom), the avocado is a hermaphrodite; the flower of this plant has both male and female parts. In the ancient world, when insects were scarcer than in later eons, plants could count on nothing but themselves to propagate. This led to the process that goes by the sophisticated botanical phrase “dichogamic protogyny.” In simpler terms, this means the flower is a hermaphrodite that has a female part that opens one day, closes at night, then opens again the next day with male characteristics, allowing it to achieve true self-pollination. Nevertheless, only relatively few species in both the plant and the animal kingdoms still boast this method of reproduction, which was much more prevalent among the earth’s earlier organisms.
Why Such a Large Seed?
The seed of the avocado is exceptionally large, and so paleobotanists have long wondered how the plant achieved disbursement. Surely such a rock-size seed wouldn’t be carried by the wind. The fruit, although not poisonous to us, is toxic to most animals alive today (including cats and dogs), causing death within hours. Even birds avoid poking their beaks into the fruit. In fact, its large pit is an example of what’s called an “evolutionary anachronism,” meaning the tree had most likely formed a relationship with some large, now-extinct animal to help scatter its seeds. Perhaps it was a large sloth or some creature with a giant mouth to eat the big avocado pits, as we would do peanuts. Dispersal of the seed, so the theory goes, was then achieved by defecation.
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It’s the Shape of What?
The English word avocado stems from the Spanish word aguacate. Actually, this was merely the Spanish pronunciation of what the Aztecs had been c
alling the fruit long before the Spaniards arrived. The Aztecs referred to it as an âhuacatl, which translates to “testicle,” since they compared the avocado’s pear shape, especially hanging as it did from trees, to part of the male anatomy. The fruit represented such a potent symbol of fertility, the Aztecs gave it a sort of X rating. Virgins were not allowed to leave their huts to see the dangling fruits amid harvesting; it was believed the fruit would make them lustful and unable to wait for a sanctioned marriage.
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AYAHUASCA
Banisteriopsis caapi
The Door of Perception
Ayahuasca is an Amazonian vine that contains a chemical known as DMT, a psychedelic compound belonging to the tryptamine group. DMT is an alkaloid substance that occurs naturally in many plants and animals, including humans, where it’s found in the neurotransmitter regions of the brain. Ayahuasca means “Vine of the Soul” or “Vine of the Dead.” The name comes from aborigines of the Amazon region and is a Spanish translation from the Quechua language. Natives used the plant for centuries in both religious ceremonies and for medicine. When brewed, the bark makes a bitter-tasting tea, a mere sip of which can induce long-lasting and far-reaching hallucinations. Shamans believed DMT allowed one to visit the astral plane and garner insights unattainable in ordinary sensory perception, such as visiting and talking with dead ancestors to gain otherworldly knowledge.