The Big, Bad Book of Botany

by Michael Largo

  The tree stood with an erect trunk about 24 feet in height and bore branches only at the crown, with leaves that were fernlike. Wattieza belonged to a genus of prehistoric species living in the mid-Devonian period that are related to current-day horsetails and ferns. It was in this period, scientists estimate, that the first seed-bearing plants spread on dry land, forming forests similar to ones today. However, wattieza itself didn’t have seeds, but rather reproduced by spores, similar to ferns. Until this new discovery, the oldest known entire tree was believed to be the Archaeopteris, a close relative of seed-bearing plants flourishing in the late Devonian period. The wattieza tree differs from this later species with its smaller trunk, fully developed leaves, lack of horizontal branches, and more limited root system.

  Although the reconstruction of such a fossil is a very difficult process, and though it may take many years to fully understand the structure and habits of early plants, it appears wattieza was the first of its kind—a life-form that literally changed the world.

  WEEPING WILLOW

  Salix babylonica

  A Grieving Tree?

  Though also known also as Babylon willow or Babylon weeping willow, the weeping willow is native to China, not ancient Babylon. Throughout history, people have grown the tree ornamentally and for lumber. The Chinese preferred to plant willow to create shelterbelts, especially around oases in the Gobi Desert, protecting cultivated plants from desert winds. Later, the plant spread worldwide (the plant was traded along the Silk Road), giving rise to many hybrid species, particularly in Europe and the United States.

  Willows are deciduous trees, medium to large in size, growing 66 to 82 feet tall. Salix babylonica has one of the most rapid growths among all trees (6 to 8 feet per year) and can live from forty to seventy-five years. It has a unique beauty with its falling, pendulous, or “weeping” branches. Its shoots are yellowish brown with small buds, while the leaves are alternate, narrow, and spirally arranged, with a light green color, about 6 inches long. In autumn the leaves turn gold-yellow, an equally beautiful sight. Flowers come in catkins, or as a slim flower cluster early in the spring. The tree is dioecious, growing male and female catkins on separate trees.

  The weeping willow is an aggressive water seeker; its roots, while searching for moisture, can break through iron pipes and overturn sidewalks. This is the reason willows are most often planted in open areas near water sources and not close to a home or building. Still, roots can be helpful if placed in the right setting to help with soil drainage and prevent erosion.

  Medical uses of weeping willows date back to ancient times. A Chinese reference dated to 400 B.C. recommends chewing the bark as an effective cure for inflammation and fever. How correct the ancients were—willow’s bark does indeed contain a chemical ingredient (acetylsalicylic acid) that is now used in aspirin. Some recent studies suggest that its bark also contains additional antioxidants and has antiseptic and immune system–boosting properties.

  Willow tree wood is also useful in arts and crafts, traditionally for wickerwork and basketry. Before the invention of plastic, willow wickerwork proved useful in the construction of many types of containers; many houses and furniture were also once made from the wood. The wood from weeping willows has also been used for charcoal manufacturing, for cricket bats, and in a dye to tan leather. In more humid European climates, as well as in eastern North America, a canker disease named willow anthracnose, or Marssonina salicicola, can drastically shorten a willow tree’s life.

  Not So Sad

  Many different symbolic meanings are attributed to weeping willows. The most common, perhaps, is one of grief. This probably originates from a Bible passage: “By the rivers of Babylon we sat down and wept when we remembered Zion. There on the willow trees we hung up our harps” (Psalm 137). Historians, however, generally agree that the trees referred to in the psalm aren’t actually willows, but are more likely poplars. Ironically, in other parts of the world, including China, the willow symbolizes growth, vitality, rebirth, and even immortality. This symbolism is born from the plant’s ability to grow easily from simply cut branches. Nevertheless, the association between weeping willows and grief and sadness has persisted throughout history, and people frequently planted the tree in graveyards during the nineteenth century.

  * * *

  Carl Linnaeus first described the tree in 1736, although he named it incorrectly. He thought it was native to old Babylon, perhaps persuaded by the biblical verse, and did not know it was native to China.

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  WELWITSCHIA MIRABILIS

  Life Comes from the Fog

  Welwitschia is a peculiar, weird, strange, bizarre, unique, but nevertheless fascinating and beautiful plant. No other plant is similar, so it is not easy to categorize welwitschia, though it is surely a monotypic, dioecious (separate male and female plants) plant of the gymnosperm group. Unlike any other herb, the tip of its stem stops growing straight at an early stage, and instead turns downward, resulting in an asymmetric and obconical shape. The plant bunches up and lies on the ground, looking like a dumped pile of old landscaping—a wholly unique growth pattern. Welwitschia is a cone-bearing plant with naked seeds, though the male flowers (microstroboli) are similar to flowering herb plants.

  The adult welwitschia has roots, a stem base, and a few leaves, and that’s all! These leaves are unique in the plant kingdom: they are original from when the herb was a seedling, but they simply continue growing, never being shed. They are broad and leathery, and lie on the ground, and in this way become torn to ribbons and tattered as they mature. The stem is woody, low, hollow, sturdy, and cone-shaped, growing up to 20 inches high. The largest known specimen was found in the Messum complex of the Gobobose Mountains, in Namibia, Africa, and was 5 feet tall. These odd plants can live five hundred to six hundred years, although some larger examples are considered to be two thousand years old. Growth occurs only during the summer months.

  Welwitschia mirabilis lives in strictly isolated communities in the Namib Desert, in a narrow strip, 600 miles long, up the coast from the Kuiseb River to Mossamedes in southern Angola. The plant shows variability, a sign it is far from going extinct. Welwitschia aren’t rare or endangered, but are still protected by law, which is wise because of their originality. Ecologically, this is a highly specialized plant, preferring to grow under arid conditions. It thrives off the regular, dense fog formed when the cold, north-moving Benguela Current meets the Namib Desert’s hot air, a radical contrast instrumental in the rise of the plant. Rainfall in the region is extremely low and erratic, so welwitschias developed an ability to reach underground waters with their long taproots. Other environmental adaptations are equally spectacular: the largest plants are growing to the south, with poor rainfall, while plants of much smaller size grow in the north, where the rains are more intense. The reason for the size difference is that the northern plants have to compete with other savanna vegetation, while those in the south have practically no competition.

  Welwitschia is not wind-pollinated, as it produces a small amount of pollen, but flowers are open in an extended period that encourages cross-pollination by beetles and some wasps. Female cones mature in spring, nine months after fertilization. Seeds are large, with papery wings that take flight with the spring winds, after the female cones disintegrate. The seeds have a limited time to germinate, only several days. Once established, the seedlings depend on the fog until the next rain. They are a determined species, that is for sure, and the plant survives some very unique environmental conditions.

  A Prehistoric Relic

  In earlier times, people used the core of the female plant as food; it is supposedly very tasty, and the reason for its original name, onyanga, meaning “desert onion.” The rest of the world was introduced to Welwitschia mirabilis by Austrian explorer and medical doctor Friedrich Welwitsch in 1859, who found it in southern Angola. The legend says that when he saw the plant, he was so excited that he knelt next to it and stared, speechless. Later,
he sent the plant to Joseph Dalton Hooker, the director of the Royal Botanic Gardens, Kew, in England, who then officially described it and named it in honor of its discoverer, even though Welwitsch had recommended the native Angolan name tumboa be used. The Latin name for the species, mirabilis, means “wonderful” or “marvelous.” The welwitschia is a kind of relic from the Jurassic period, which partially explains many of its unique qualities.

  WINTERGREEN

  Gaultheria procumbens

  Minty Cover

  Gaulteria procumbens, also known as American wintergreen, is a woody, rhizomatous, creeping, evergreen ground cover in the heath family of Ericaceae. It’s native to woodlands in eastern North America, from Georgia and Tennessee to Newfoundland and other parts of Canada. Its erect stem can grow up from the rhizomes to be 3 to 6 inches tall, while the glossy, elliptic, leathery, dark green leaves usually grow about 2 inches in length. It makes an attractive ground cover that bears comparatively large, waxy, white flowers approximately 3 to 4 inches long. The flowers bloom in early summer, forming between the leaf axis, and then produce bright red berries. The berries are edible and can persist on the plant along with its green leaves throughout the winter, from which comes the name wintergreen. Both the leaves and fruits have a minty taste and aroma. The essential oil extracted from wintergreen’s foliage has stimulating, astringent, and diuretic effects when consumed. Berries possess a minty flavor all their own, and many make herbal teas from the leaves and branches. Wintergreen is also a popular ice cream flavor in regions where the plant grows.

  Wintergreen grows best in organically rich and slightly acidic soil. It likes an even amount of moisture and must be in areas with drainage, although well-established plants may tolerate drier soils. The plant requires full to partial shade and withers quickly in full sun. However, the herb does best in climates with cool summers. Wintergreen regenerates primarily by spread of its rhizomes, which lie close to the surface. While it can’t survive forest fires, a brief fire will not kill it off completely, as its shallow rhizomes allow it to rejuvenate even if its leaves have been destroyed or consumed. Gaultheria procumbens is a food for many animals, and for some it is the only source of food through winter. The survival of berries in winter is very important, as it is one of the rare green foods animals can eat when nothing else is available.

  A Plant of Many Names

  The genus name of wintergreen, Gaultheria, was given in honor of Jean-Francois Gaultier, who was a special king’s physician for the French colony of Quebec during the period from 1742 until 1756. He was also an avid plant collector and botanist. There are also many other common names given to this plant, depending on the region: American mountain tea, Canada tea, boxberry, canterberry, chickenberry, creeping wintergreen, deerberry, gingerberry, partridge berry, squaw vine, teaberry, and spiceberry, to name but a few.

  WITCH HAZEL

  Hamamelis

  Exploding Seeds

  Witch hazel has about fifteen medical uses, each proven useful in treating a number of different problems. Native Americans knew of its many health benefits and treated the plant with great respect. Also known as Hamamelis, witch hazel is a genus of flowering plants from the family Hamamelidaceae. Three species are known in North America, one in China, and one in Japan. North American species are also known as winterblooms.

  The plant typically grows as a deciduous shrub, reaching 9 to 26 feet tall. It has oval, alternately arranged leaves, 1½ to 6 inches long and 1 to 4 inches wide. The leaves are wavy in the center, with a smooth margin. The plant’s genus name means “together with fruit,” which refers to the blooming of its flowers alongside the previous year’s maturing fruits. Most of the species bloom during January to March, except for Hamamelis virginiana, which produces flowers from September to November. The flowers have four slender petals, with pale to dark yellow, red, or orange colors, and comprise two-part capsules, less than ½ inch long, each half of which contains only one black seed. The capsules split in two when mature. The opening of the pod, however, is violent, such that it literally combusts with an explosive sound as loud as a firecracker. This causes the seeds to be ejected to distances of more than 30 feet from the mother plant. This process has led to another nickname, snapping hazel.

  The witch part of the plant’s name actually comes from the Old English word wiche, or wice, meaning both “pliant” and “bendable.” The name witch hazel was used in England as a synonym for wych elm, or Ulmus glabra, but Americans have simply extended the familiar name to the newfound plant. Witch hazels are very popular ornamental plants, mostly grown for their rich-colored clusters.

  The Plant as Medicine

  Witch hazel contains the chemical tannin, which is partly amorphous and partly crystal. It also has gallic acid, physterol, fat, resin, and other bitter and odorous elements that make it widely used in medicine, both traditional and modern. The plant provides many health benefits:

  •Controls blemishes and spots

  •Shrinks bags under the eyes

  •Heals and soothes diaper rash

  •Relieves varicose veins

  •Reduces and soothes external hemorrhoids

  •Soothes poison oak and poison ivy

  •Treats chicken pox blisters

  •Soothes and treats bad sunburns

  •Soothes and in some instances prevents razor burn

  •Heals bruises

  •Moisturizes dry skin

  •Heals and soothes various bruises and cuts

  •Heals bug bites

  •Refreshes tired eyes

  •Serves as a natural (and pleasurable) deodorant

  WOLFFIA ANGUSTA

  Big Potential in a Small Package

  The only way to identify the species of a Wolffia flower is to look at it with a microscope; otherwise you will see only small green spots on the water surface where they grow. Scientists consider the Wolffia the smallest flower in the world. Its fruit, called utricle, is also the smallest known, with an average weight of .00007 grams. The microscopic plant is composed of 40 percent protein, similar to soybeans. The people of Thailand, Burma, and Laos use it as a food supplement, although it takes a forest of it to make one meal.

  Wolffia is a rootless, freely floating water plant, preferring freshwater. It’s shaped like a blob, and its size says everything: 0.01 inch long and a fraction of that wide. Native to Southeast Asia, Australia, and the Pacific, this amazing specimen of life belongs to the family Araceae (or Lamnaceae), and is a perennial, with round-edged green leaves. It blooms in summer, with flowers weighing only as much as two grains of sand. In addition to its flowers being speck-size, they are even harder to notice because they are nearly the same green color as the plants’ leaves—and it would take somewhere around five thousand of its tiny flowers to fill one thimble. Wolffia angusta belongs to a genus of about 10 species, commonly named aquatic plants or thalli.

  Wolffia often grows in colonies, forming a dense mat on the water’s surface. They are angiosperms and reproduce vegetatively. Each plant (or frond) is able to reproduce several times before dying. Its tiny seeds are freeze-resistant. Wolffia angusta is often referred to as a watermeal, and many have wrongly identified it as duckweed. It is rich with proteins, and nearly all aquatic animals and fish prey on the plant.

  Solving the World’s Problems

  The significance of Wolffia is much larger than its size. Some recent studies show that Wolffia angusta has a great potential to help solve some serious problems, including the bioremediation or filtering of polluted waters, since the plant can absorb a number of known harmful chemicals and covert them into nutrients. Some have even identified the plant as an excellent source of biofuel, which could hopefully reduce our dependence on oil. The plant grows fast, and people have begun trials to find an efficient means to mass produce it for its protein and inexpensively help end world hunger. Who knows? The world’s smallest flower might prove to be nature’s solution to one of the world’s biggest problems.

>   YERBA

  Ilex paraguariensis

  The Miracle Tea

  What has the health benefits of tea, the strength of coffee, and the euphoria of chocolate, all in one? Yerba leaves contain theophylline, caffeine, and theobromine, all of which are present in coffee, tea, and chocolate. However, unlike tea, drinks made from yerba have much lower levels of tannin, lessening the bitter taste; unlike coffee, it’s not very acidic and oily, so you won’t get jitters or stomach woes.

  A species belonging to the family Aquifoliaceae and native to subtropical South America, yerba is traditionally consumed as the beverage maté. The Guarani people of Paraguay were the first to use and cultivate the plant prior to colonization. Yerba starts its life as a shrub and then, as it matures, grows into a tree up to 49 feet tall. Its leaves are evergreen, with serrated margins, 2 to 4 inches long. Its flowers are greenish white and small, and have four petals each. The fruits or drupes are red, and less than ¼ inch in diameter. The original name comes from the Spanish yerba and Portuguese erba, both meaning “herb,” and refers mostly to the leaves that contain mateine, which remain the only part of the plant harvested commercially.

  Historically, a broader consumption of yerba started in the sixteenth century, when Spanish colonizers cultivated it in Argentina, Bolivia, Chile, Brazil, and Peru. In the seventeenth century, Jesuits established the first plantations in Argentina, which is now the largest producer of yerba.