• Bauer, K., Grauvogel-Stamm, L., Kustatscher, E., and M. Krings. 2013. "Fossil Ginkgophyte Seedlings From The Triassic of France Resemble Modern Ginkgo biloba. BMC Evolutionary Biology 2013, 13:177 doi:10.1186/1471-2148-13-177. Accessible On-Line.

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Osmunda claytoniana. Image from Wikimedia Commons.

I recently received an e-mail message from Brian Ottway of Portugal regarding the fern Osmunda claytoniana. According to an article in the American Journal of Botany (1998), Osmunda fronds from Triassic deposits in Antarctica are virtually identical to modern O. claytoniana. The fossil fern has been named O. claytoniites and dates back 200-250 million years ago. Modern Osmunda claytoniana is native to the eastern United States, Canada and eastern Asia. Fossil evidence indicates that this species had a circumboreal distribution across North America, Europe and Asia.

• Phipps, C.J., Taylor, T.N., Taylor, E.L., Cuneo, N.R., Boucher, L.D., and and X. Yao. 1998. "Osmunda (Osmundaceae) From The Triassic Of Antarctica: An Example Of Evolutionary Stasis." American Journal of Botany 85 (6): 888-895.

3. The World's Most Massive Living Thing

Prior to the discovery of ancient bristlecone pines and creosote bush rings, the world's record for longevity went to the magnificent giant sequoia (Sequoiadendron giganteum) of the western slopes of the Sierra Nevada. The greatest authenticated age of a giant sequoia, derived from counting annual rings on a cut stump, was nearly 3,200 years. Although it may fall short of the world's oldest, a giant sequoia in Sequoia National Park has the undisputed record for the world's most massive living thing. The largest tree, named General Sherman, is 272 feet (83 m) tall with a massive trunk 35 feet (11 m) in diameter and 109 feet (33 m) in circumference at the base. Even more remarkable is the fact that at a point 120 feet (36 m) in the air the trunk of General Sherman is still 17 feet (5 m) in diameter. It has been estimated to contain over 600,000 board feet of timber, enough to build 120 average-sized houses. In fact, a single giant sequoia may contain more wood than is found on several acres of some of the finest virgin timberland in the Pacific Northwest. The trunk of General Sherman alone weighs nearly 1400 tons. By way of comparison, this is roughly equivalent to 15 adult blue whales, 10 diesel-electric train locomotives, or 25 average-sized military battle tanks.

Another conifer species called the Montezuma bald cypress (Taxodium mucronatum) occasionally grows into a huge tree. One enormous specimen of this tree grows in the churchyard of Santa Maria de Tule near Oaxaca, Mexico. Called "El Gigante" by the locals, it is one of the most massive of all living things with a trunk circumference of 140 feet (43 m), larger than the General Sherman giant sequoia. With a diameter of 50 feet (15 m), the trunk of this spectacular tree is literally the size of a house. This gigantic tree was once thought to be 10,000 years old, but botanists now consider it to be a youngster of only 1,500 to 2,000 years.

Some flowering trees such as the African baobab (Adansonia digitata featured in the movie "The Gods Must Be Crazy--Part II"), the South American ombu (Phytolacca dioica) and the Indian banyan (Ficus benghalensis) also have enormous trunks up to 100 feet (30 m) or more in circumference, but do not grow as tall. One large baobab trunk can store 25,000 gallons of water weighing 100 tons. According to E. Palmer and N. Pitman (Trees of South Africa, 1961), a tree with a volume of 7,500 cubic feet may contain 30,000 gallons of water. This amount of water alone would weigh an astonishing 120 tons. The Indian banyan also has the record for the world's largest (spreading) tree crown, with 1000 pillar-like prop roots supporting massive limbs that cover four acres. Alexander the Great reportedly camped with an army of 7,000 soldiers under such a fig tree. Other trees of the tropical rain forest, such as the kapok tree (Ceiba pentandra) of Central and South America, also develop huge buttressed trunks.

Based on measurements of height, canopy spread and trunk diameter, a Moreton Bay fig (Ficus macrophylla) in Glendora, California is the largest cultivated tree in California with a point score of 700. Enormous Moreton Bay figs in Santa Barbara and Balboa Park (San Diego) are the 2nd and 3rd largest. For comparison, the General Sherman giant sequoia of Sequoia National Park has a total point score of 1800!

The mycelium of some forest fungi can extend enormous distances. A single individual of Armillaria bulbosa has been discovered that permeates more than 30 acres of forest soil in northern Michigan. Some scientists speculate that it was spawned by a single spore thousands of years ago. Another species of Armillaria (A. ostoyae) in the Blue Mountains of eastern Oregon was recently found to consist of a subterranean mycelial network with erect, above-ground mushrooms covering more than 2,000 acres of forest soil. The largest colonies of Armillaria have been estimated to be 1500 to 2400 years old. See recent article by Dr. Ramesh Maheshwari of the India Institute of Science in Bangalore: "The Largest and Oldest Living Organism," Resonance April 2005: 4-9.

Mushroom fruiting bodies of the forest fungus Armillaria mellea

These fungal monstrosities are rivaled in total size and mass by a 106 acre, 6,000 ton stand of genetically identical quaking aspen (Populus tremuloides) in the Wasatch Mountains of Utah. The aspen clone is connected (in part) by a common root system, and has literally climbed over mountains and across meadows. The age of this giant clone has been estimated at 10,000 years or more. Any discussion of massive clonal colonies should also include the conjoined polyps of coral reefs. However, the question still remains: Do these clonal colonies qualify as a single individual, as in the 1400 ton General Sherman?

4. The World's Tallest Tree

The world's record for the tallest tree goes to another cone-bearing tree native to California, the coast redwood (Sequoia sempervirens). In fact, the tallest living redwood on record stands 379 feet (116 m), 64 feet (20 m) taller than the Statue of Liberty. The California redwoods are rivaled in size by the amazing flowering Australian mountain ash (Eucalyptus regnans). The record for the tallest tree of all time has been debated by botanists for more than a century. Some amazing claims for towering Douglas fir (Pseudotsuga menziesii) and E. regnans exceeding 400 feet (122 m) have never been substantiated by a qualified surveyor. In 1872, a fallen E. regnans 18 feet (5.5 m) in diameter and 436 feet (133 m) tall was reported by William Ferguson near Watts River, Victoria. The tree had fallen after a brush fire and was measured by Ferguson with a tape. There is some controversy over the exact length, but if correct this would certainly be the tallest (or perhaps longest) fallen tree on record. According to the International Society of Aboriculture, Australian Chapter, a record-breaking E. regnans at Thorpdale, Victoria was reportedly 374 feet (114 m) tall. It was measured with a theodolite (cf. transit) in the 1880s. Unfortunately, this remarkable tree was cut down. It was almost six feet (2 m) taller than the current tallest living redwood. According to the monograph on Eucalyptus by Stan Kelly (Volume 1 of Eucalypts, 1977), trees of E. regnans well over 300 feet (91 m) tall have been measured, but the tallest tree known to be standing at present is 322 feet (98 m).

5. The World's Hardest & Heaviest Wood

Most of the other remarkable plant records go to the flowering plants. This is not surprising since flowering plants have colonized practically every conceivable habitat on earth, from vast submarine meadows in oceans and bays to arid deserts and windswept alpine summits. At least a dozen species of flowering trees called "ironwoods" hold the title of world's heaviest wood. Wood is composed of dead cells of a tree trunk, particularly the inner xylem tissue when the bark is removed. The weight of wood is essentially due to the cellulose and lignin in the cell walls of billions of cells. Ironwoods all have wood with very dense, heavily lignified cells with little or no air spaces in the cell cavities (lumens). The pure cell wall material has a specific gravity of about 1.5, and the heaviest and hardest ironwoods approach 1.4. Since pure water has a specific gravity of 1.0, ironwoods with specific gravities greater than 1.0 will sink in water. Certainly one of the world's heaviest and hardest ironwoods is the Caribbean tree called lignum vitae (Guaiacum officinale), with a specific gravity of 1.37. The name lignum vitae means "wood of life," owing to the medicinal properties of the sweet-smelling resin. The density and high resin content of the wood make it extremely resistant to friction and abrasion and account for its remarkable self-lubrication properties. Under certain conditions it actually wears better than iron. In fact, the highly-prized wood was used for end grain thrust blocks which lined the propeller shafts of steamships. [Note: The Guinness Book of World Records lists the South African black ironwood (Olea laurifolia) as the heaviest wood with a specific gravity of 1.49. This is rather doubtful since the specific gravity of pure cell wall material is 1.5 (i.e. without any cellular structure), and samples of Olea laurifolia I have tested only weighed in at about 1.11.] By way of contrast, cork bark from the European cork oak (Quercus suber) has a specific gravity of 0.24; and the tropical American balsawood tree (Ochroma pyramidale) is one of the world's softest and lightest woods with a specific gravity of only 0.19.

There are approximately 300,000 species of described flowering plants in the world, and they range in size from diminutive alpine daisies only a few inches tall to massive eucalyptus trees in Australia over 300 feet (91 m) tall. But the undisputed world's smallest flowering plants belong to the genus Wolffia, minute rootless plants that float at the surface of quiet streams and ponds.

Each minute Wolffia plant is shaped like a microscopic green football with a flat top. An average individual plant of the Asian species W. globosa, or the equally minute Australian species W. angusta, is small enough to pass through the eye of an ordinary sewing needle, and 5,000 plants could easily fit into a thimble. It is difficult to say which is the smaller of the two, but perhaps W. globosa may be slightly smaller. An average individual plant is 0.6 mm long (1/42 of an inch) and 0.3 mm wide (1/85th of an inch). It weighs about 150 micrograms (1/190,000 of an ounce), or the approximate weight of 2-3 grains of table salt. One plant is 165,000 times shorter than the tallest Australian eucalyptus (Eucalyptus regnans) and seven trillion times lighter than the most massive giant sequoia (Sequoiadendron giganteum). Another mind-boggling comparison is the size or volume of a single wolffia plant: roughly intermediate between a water molecule and the planet earth.

If a water molecule is represented by 100, then a wolffia plant is about 1020 power larger than the water molecule. The earth is about 1020 power larger than a wolffia plant, or 1040 power larger than the water molecule.

Wolffia plants also produce the world's smallest flower, a bouquet of one dozen plants will easily fit on the head of a pin and two Wolffia angusta plants in full bloom will fit inside a small printed letter "o" on this page.

Wolffia The Size Of A Bacterial Cell Wolffia The Size Of A Cycad Sperm A recent article by J. Travis in Science News Vol. 155 (April 17, 1999) discusses a remarkable new species of sulfur bacteria from the greenish ooze of ocean sediment off the coast of Namibia in southwestern Africa. Sulfur bacteria oxidize sulfur compounds to produce their energy-rich ATP molecules. The spherical bacteria have diameters ranging from 0.1 to 0.75 mm, definitely within the size range of some species of Wolffia. The bacteria were discovered in sediment samples by Heide Schulz of the Max Planck Institute for Marine Microbiology in Bremen, Germany (see the April 16, 1999 issue of Science). The new species is named Thiomargarita namibiensis, or sulfur pearl of Namibia. When light shines on the bacterial cells, they glisten white from light reflecting off sulfur inside them (see the image above). Because of their size and light-reflecting properties, the bacteria are visible to the naked eye, roughly the size of a printed period or the size of an average grain of table salt (NaCl). But who would ever believe that a multicellular flowering plant could be as small as one prokaryotic bacterial cell. This is certainly the case with Wolffia globosa, especially if you consider the size of a single daughter plant that has broken away from the parent plant by budding (see the images above). And although it is the ultimate in reduction of a flowering plant, it actually has minute guard cells and stomata on its upper (dorsal) surface. Any way you look at these amazing records; a giant bacterial cell or a microscopic flowering plant, they are truly wonders of the world. A single sperm cell from Zamia roezlii, an interesting cycad endemic to rain forests of Colombia, is about 0.4 mm in length and is visible to the unaided eye. In fact, it is almost as large as one entire wolffia plant. It consists of several spiral bands of 20,000 to 40,000 cilia at one end. The pulsating beat of these cilia may help to propel the sperm through the pollen tube on its journey to fertilize the egg.

Each wolffia plant produces a microscopic flower (consisting of one stamen and one pistil) inside a small cavity on the upper side of the plant body. Tiny wolffia plants are commonly dispersed on the feet of water fowl, tucked neatly under the duck's bodies during flight. In the southeastern United States there are records of wolffia plants being carried by a tornado, and they have been reported in the water of melted hailstones. By way of comparison, the world's largest flower is produced by a parasitic plant (Rafflesia arnoldiii) native to the Malay Archipelago. This bizarre plant lives inside climbing vines of the tropical rain forest. Like a gigantic erupting pimple, a rafflesia flower bud breaks through the bark of the host vine and expands into an enormous foul-smelling blossom up to three feet (0.9 m) in diameter and weighing up to 20 pounds. In fact, it is sometimes called the "stinking corpse lily."

What Is The Largest Flowering Plant?

According to the Guinness Book of World Records, "The Largest Blossoming Plant" is an enormous Chinese wisteria vine (Wisteria sinensis) growing at a private residence in the quaint city of Sierra Madre in southern California. The Japanese wisteria (W. floribunda) is very similar genetically and the two species hybridize. Both species are invasive vines (lianas) that are naturalized in the southeastern United States. Since flowering plants (angiosperms) produce blossoms, this record could also be stated: "The World's Largest Flowering Plant." The vine was planted in 1894 from a one gallon pot. It covers nearly an acre and weighs over 250 tons. During a five week blooming period it produced over 1.5 million blossoms. It is one of the Guinness Book of World Records "Seven Horticultural Wonders of the World":

For a showy, cultivated flowering vine, the famous Sierra Madre wisteria is certainly one of the largest; however, in technical botanical terms there are flowering trees that rival or exceed this vine in massiveness. The Australian mountain ash (Eucalyptus regnans) can exceed 300 feet in height. In fact, some of the tallest trees rival the California coast redwood (Sequoia sempervirens) in height. As I stated above, the South African baobab tree (Adansonia digitata) is a massive flowering plant. The enormous trunk may exceed 100 feet (30 m) in circumference with a volume of 7,500 cubic feet. It reportedly can store 25,000 gallons of water weighing 100 tons. The Indian banyan (Ficus benghalensis) has the record for the world's largest (spreading) tree crown, with 1000 pillar-like prop roots supporting massive limbs that cover four acres. Figs (Ficus) produce thousands of ovoid, "fruit-shaped" structures called syconia, each containing hundreds of minute, apetalous, unisexual flowers. An aspen clone in the Wasatch Mountains of Utah is composed of 47,000 stems of genetically identical aspen trees (Populus tremuloides), with a total weight of 6 million kilograms (6,500 tons). It is connected (in part) by a common root system, and has literally spread across 106 acres of forests and meadows. It started out as one individual male plant thousands of years ago and has developed asexually by suckering, where new adventitious stems arise from a gigantic spreading root system. The flowers of some of these record-breaking tree species have inconspicuous, unisexual, apetalous flowers that could hardly be recognized as blossoms; however, they are nonetheless true flowering plants. Most people associate the word "blossom" with conspicuous, showy flowers, so the record "Largest Blossoming Plant" is probably horticulturally fitting for the spectacular Sierra Madre wisteria, even though it is not entirely botanically accurate.

The Stinking Corpse Lily: World's Largest Flower

A related family of parasitic flowering plants (the Rafflesiaceae) contains the "stinking corpse lily" (Rafflesia arnoldii), the world's largest individual flower and truly a wonder of the plant kingdom. It has been called the "giant panda of the plant world" because this rare and endangered species only occurs in the rain forests of Sumatra and Borneo in the Malay Archipelago. Unlike most flowering plants, it has no leaves or stems and grows endoparasitically within the woody stems of its host vine Tetrastigma, a relative of the grape. Unless you saw evidence of an old blossom, you could walk right past a Tetrastigma vine without ever knowing that a complete Rafflesia plant lives inside its stem. Occasionally a large flower bud resembling a pale orange cabbage breaks through the bark of the host vine and expands into an enormous blossom up to 3 feet (0.9 m) in diameter and weighing up to 25 pounds (11 kg). The gigantic unisexual flower has five fleshy red lobes (sepals) spattered with raised white spots. With an odor reminiscent of a stinking corpse, the blossom attracts carrion beetles and flies which shuttle the pollen from male to female flowers. A single female flower may produce up to four million seeds which are dispersed by a variety of animals, from ants, tree shrews and squirrels, to the feet of wild pigs and Asian elephants. If a seed becomes lodged in a moist crevice on its host vine, it germinates and penetrates the host tissue where it proliferates into a network of microscopic filaments of cells. These fungus-like networks of vascular tissue eventually give rise to a mammoth blossom that pushes out through the host stem, making Rafflesia one of the most intriguing and unusual plants on earth. The chances of a seed finding a host vine are slim, and massive deforestation has further decreased the odds of this remarkable event. Recently the governments of Indonesia and Malaysia have begun to recognize the marketable curiosity value of this plant and ecological preserves are being established.

Illustration by Graphic Artist E.M. Armstrong.

Copyright (C) ma_suska (2007) Courtesy of Wikimedia Commons.

Agave americana The inflorescence in left image is about 30 ft. tall. This species is monocarpic: It flowers and bears fruit only once and then dies. Century plants (Agave) and some yuccas (Yucca whipplei) bloom after 8-10 to 20 years or more and then die. Most of the Agave's resources go into the enormous, rapid-growing flower stalk. At the base of the withering leaves, small "pups" will take the place of the dying mother plant. Most varieties of bamboos in cultivation are clones derived from a single plant that may be traced back to one seed. This may explain why some cultivated bamboos have the same flowering cycle and mortality as populations on different continents. By far the majority of bamboo species are not monocarpic, i.e. they do not flower gregariously and then die.

The most remarkable carrion arum is the titan arum or bunga bangkai "corpse flower" (Amorphophallus titanum). Native to equatorial tropical rain forests of Sumatra, Indonesia, this amazing plant flowered at the New York Botanical Garden in 1937. At its maximum development, a spadix over 8 feet tall (2.4 m) emerged from a huge vase-shaped, pleated spathe over 4 feet (1.2 m) tall and 12 feet (4 m) in circumference. This floral giant developed from a tuber measuring 6 feet (2 m) in circumference and weighing over 100 pounds (46 kg). According to B. Meeuse and S. Morris (The Sex Life Of Flowers, 1984), the enormous blossom generates such an overwhelming smell that people have been known to pass out from taking too close a whiff.

In some carrion flowers the insects are lured into dark openings leading to the putrefying interior where they become trapped among the floral organs. This strategy insures cross pollination, especially when the male anthers release pollen several days after the female stigma is no longer receptive. When the imprisoned insects are allowed to leave they are given a thorough dusting of fresh pollen to be taken to a different plant. One of the classic insect-trapping carrion flowers is the European Dutchman's pipe (Aristolochia clematitis), a member of the birthwort family (Aristolochiaceae). The unusual common names are derived from the curious blossoms with a shape reminiscent of Sherlock Holmes' pipe, and an old herbal remedy. Some species in this family have aromatic roots that were reputedly used as a purgative to induce labor, a questionable practice that is not recommended. The curious blossoms of some species superficially resemble a human fetus in the womb, and the plants were once thought to facilitate child birth. During medieval times, various ailments were treated with plants that resembled certain afflicted parts of the body. This practice was called the "Doctrine of Signatures," and became the basis of medical treatment for centuries to come. The striking, tubular flower of Dutchman's pipe is held upright as it emits a foul, pungent odor. Small gnats land on the vertical upper calyx surface but slip down through the floral tube and into the inflated "pipe chamber" due to slippery wax granules on the inner surface. Dense, downward-pointing hairs in the floral tube prevent the gnats from climbing out. During their incarceration the gnats receive rations of nectar. Several days later, when the anthers release pollen, the jail hairs wilt and the flower tilts horizontally, allowing the pollen-laden gnats to walk out of their prison, and into another receptive floral trap on a different plant.

7. The World's Smallest & Largest Fruit

Wolffia also produces the world's smallest fruit, although this record is not as yet recognized in the Guinness Book. Each one-seeded fruit is about the size of a cuboidal grain of ordinary table salt (0.3 mm long) and weighs about 70 micrograms (1/400,000 of an ounce). It is roughly five billion times lighter than a 900 pound squash.

Although duckweeds of the genus Lemna have plant bodies a little larger than wolffia, the one-seeded fruits of some species are almost as small. The photo at left shows a minute fruit protruding from a budding pouch at the top of a tropical duckweed (L. aequinoctialis). The head of an ordinary straight pin is shown as a size relationship.

According to Cucurbits, the official newsletter of the World Pumpkin Confederation, a 1993 record-breaking pumpkin weighed in at 836 pounds and a giant squash tipped the scales at just over 700 pounds. One year later at the "gourd olympics" in Port Elgin, Ontario, the reign of the pumpkin was broken by a 900 pound squash. There have been other unofficial records for pumpkins exceeding 900 pounds. To enter your prize pumpkin in the official World Pumpkin Confederation Annual Weigh-Off, it must be cream-yellow to orange; if it is green to gray or mottled in color it must be entered as a squash. Many pumpkins are varieties of Cucurbita pepo, although the largest pumpkins probably come from C. maxima.

The World's Largest Bean Pod & Seed Cones

Left: The world's largest been pods come from woody vines or lianas of the genus (Entada). They are native to the rain forests of the Old and New World tropics. The largest species is called the sea heart (E. gigas), and the pods may be 5 feet (1.5 m) long. The woody, heart-shaped seeds of Entada gigas are carried by torrential rains into rivers and eventually into the sea where they often drift to the shores of distant continents and islands. Right: Although technically not a fruit, California's coulter pine (Pinus coulteri) has one of the largest seed cones on earth. Of all the more than 100 species of pines in the world, this is one of the most massive cones. They may be up to 14 inches (36 cm) long and weigh more than 8 pounds (3.6 kg). Other pines, such as the sugar pine (P. lambertiana) have longer cones, but they have flimsy cone scales and do not weigh as much. The heavy cones of Coulter pine with talon-like, curved scales are definitely a hazard to anyone standing or sleeping under a cone-laden limb. Seed cones of the Australian bunya-bunya tree typically weigh 10 pounds (4.5 kg) or more, and definitely pose a danger to mortal humans if you stand under a large tree during "cone-dropping" season. The undisputed world's largest seed cones are produced by tropical cycads of the genera Lepidozamia and Encephalartos. The largest cones are three feet (0.9 m) long and weigh up to 95 pounds (45 kg). The world's largest legume fruits (bean pods) are produced by the tropical liana Entada. The longest pods of the Central American E. gigas may be up to 5 feet long (1.5 m). This gigantic woody vine is truly like Jack's fabulous bean stalk. In Costa Rica it is called "monkey ladder" or "escalera de mono." The woody seeds of E. gigas are called "sea hearts" and are often washed down streams to the sea where they drift across the ocean to distant continents. Familiar edible legume pods in the background include green beans, peanuts, soybeans and snow peas.   Diversity of Flowering Plants     The World's Longest Bean Pod   At Quail Botanical Garden in Encinitas (San Diego County) the trail near the bunya-bunya trees is closed during August and September.   More About The Araucaria Family   The massive seed cone of the African Encephalartos manikensis. The World's Largest Sperm Cycads also have the record for the world's largest sperm. A single sperm cell from Zamia roezlii, an interesting cycad endemic to rain forests of Colombia, is about 0.4 mm in length and is visible to the unaided eye. It is roughly the size of an average grain of table salt or a dust mite. In fact, it is almost as large as one entire wolffia plant! It consists of several spiral bands of 20,000 to 40,000 cilia at one end. The pulsating beat of these cilia may help to propel the sperm through the pollen tube on its journey to fertilize the egg. Sea Heart: World's Longest Bean Pod Cycads From The Time Of Jurassic Park Cycads, Plate Tectonics & Continental Drift 8. The World's Largest Hitchhiking Fruit Seed-bearing fruits that cling to the bodies of animals are very effective methods of seed dispersal in the plant kingdom. There are literally hundreds of plant species with hitchhiking seed pods, but some of the largest are from the North American devil's claw (Proboscidea). The devil's claw fruit is technically a drupaceous capsule with a woody inner part surrounded by a fleshy layer. The rather sinister common name of "devil's claw" refers to the inner woody capsule which splits open at one end into two curved horns or claws. Each capsule contains about 40 black seeds which are gradually released when the claws split apart. They are also called "elephant tusks" and readily cling to the hooves of grazing animals or your shoes if you happen to step on them. In some areas of the southwestern United States they are a nuisance to sheep ranchers because they get entangled in the fleece. In his fascinating book, Plants and Planet (1974), Anthony Huxley (son of Julian Huxley) eloquently describes the hitchhiking pods as "hookers." The fresh green pods (and dried black seed capsules) were important items in the cultures of many Indian tribes of the southwestern United States, and are still used to this day for food and in basketry. The striking seed pods of the domesticated, white-seeded cultivar P. parviflora ssp. parviflora var. hohokamiana have claws up to 15 inches (38 cm) long. Multiclawed forms have also also selected by native Americans because the horns split into 3-4 claws. The long claws are soaked in water and split into leathery strands. They provide durability and intricate black designs in tightly woven baskets made from sun-bleached yucca leaves (often Yucca elata). The devil's claw is also known as "unicorn plant" referring to the large, hornlike fruit before is has split open. The seed capsules of devil's claws are clearly adapted for hitchhiking on the hooves of large grazing animals; however, with the exception of introduced livestock and people (and possibly desert bighorn sheep), there are few native North American animals living within the present range of devil's claws that are capable of dispersing these large hitchhikers. It is possible that the range of some large North American grazers, such as antelope, bison, deer and elk once overlapped the range of devil's claws thousands of years ago. It is also possible that devil's claw dispersal by grazing mammals may be a North and South American anachronism, or an occurrence that is out of its proper time in history. During the past one million years of the Pleistocene Epoch, the Americas were rich in large mammals (such as giant ground sloths) which are now extinct. Assuming devil's claw plants existed over 600,000 years ago, were some of these ancient mammals the true carriers of these hitchhiker pods? A similar anachronism occurs in the New World tropics of Central and South America, where the natural dispersal agent for some large seed pods are unknown. Devil's Claws: Hitchhikers On Big Animals Wayne's Word Top 17 Hitchhiking Plants The Cocklebur: Nature's VelcroŽ 9. The World's Largest Vegetable If you define a botanical vegetable as an edible part of a plant that clearly excludes seed-bearing fruits, then there are a number of possible contenders for this coveted record. [Note: We are not using the Webster's definition which states that a vegetable is an edible plant part typically eaten with your main entree, but not as a dessert.] Remember that pumpkins and squash must be disqualified because they are seed-bearing fruits even though they may be eaten with your main entree. Some of the top contenders for this record are the blades of large brown algae called kelp, and the tender leaves of the horseradish tree (Moringa oleifera), not to be confused with the true horseradish of the mustard family (Armoracia lapathifolia). Perhaps a more logical contender for this record are the massive subterranean yams of the genus Dioscorea, some of which may weigh over 120 pounds (54 kg). In order to reduce the size of this file and the time it takes to load, the "World's Largest Vegetable" section is placed on another file under the September 1996 Issue Of Noteworthy Plants: See: The World's Largest Vegetable 10. The World's Smallest & Largest Seed Certain epiphytic orchids of the tropical rain forest produce the world's smallest seeds, up to 35 million per ounce. One seed weighs about one 35 millionths of an ounce (1/35,000,000) or 0.81 micrograms. Some seeds are only about 1/300th of an inch long (85 micrometers). [The resolving power for an unaided human eye with 20-20 vision is just under 0.1 mm.] Orchid seeds are dispersed into the air like minute dust particles or single-celled spores, eventually coming to rest in the upper canopy of rain forest trees. The world's largest seed comes from the coco-de-mer palm (Lodoicea maldivica), native to the Seychelles Archipelago in the Indian Ocean. Although it belongs to a different genus from true coconut palms (Cocos), this enormous seed is often called the "double coconut." A single seed may be 12 inches (30 cm) long, nearly three feet (0.9 m) in circumference and weigh 40 pounds (18 kg). It should be noted here that the largest seed does not have the largest embryo. In fact, palm seeds are mostly composed of endosperm tissue and generally have relatively small embryos (see photo link below). Small seeds. Mustard family (Brassicaceae): Black mustard (Brassica nigra). Orchid family (Orchidaceae): Coral-root orchid (Corallorhiza maculata). Duckweed family (Lemnaceae): Watermeal (Wolffia angusta), a one-seeded fruit called a utricle. Poppy family (Papaveraceae): Opium poppy (Papaver somniferum). Without any doubt, the orchids have the record for smallest seeds. The seeds of some species are no larger than fungal spores and occur in a loose cellular sheath. Since the seeds have no endosperm and underdeveloped embryos, there are practically no food reserves. In order to germinate under natural conditions, they must establish a symbiotic relationship with a compatible mycorrhizal fungus. During early stages of development, the fungus supplies critical nutrients to the orchid seedling. Later the orchid may become fully independent, or it may retain its mycorrizal relationship throughout its life. The above coral-root orchid seed (Corallorhiza) grows into a nonphotosynthetic mycotrophic wildflower. It absorbs carbohydrates and minerals from its fungal host, which in turn absorbs these vital nutrients from the roots of nearby forest trees. Orchid seeds are also grown under aseptic conditions in nutrient agar, similar to bacterial and fungal cultures. Wolffia certainly has the record for smallest fruits which are not much larger than grains of ordinary table salt (NaCl). The single seed inside is almost as large as the fruit; therefore, wolffia seeds are not as small as orchid seeds. Microscopic view of the seed of a coral-root orcid (Corallorhiza maculata). The individual seed is only about 0.2 mm in diameter. In fact, there are unusual bacterial cells that are larger than this orchid seed. The resolving power for an unaided human eye with 20-20 vision is about 0.1 mm. With its cellular sheath (seed coat) removed, this seed is barely visible to the naked eye. Certain epiphytic orchids of the tropical rain forest produce the world's smallest seeds weighing only 35 millionths of an ounce. One seed capsule from a single flower may contain up to four million seeds. They are dispersed into the air like minute dust particles or single-celled spores, eventually coming to rest in the upper canopy of rain forest trees. The seeds of some species are no larger than fungal spores and occur in a loose cellular sheath. Since the seeds have no endosperm and a minute, undifferentiated embryo, there are practically no food reserves. In order to germinate under natural conditions, they must establish a symbiotic relationship with a compatible mycorrhizal soil fungus. During early stages of development, the fungus supplies critical nutrients to the orchid seedling. Later the orchid may become fully independent, or it may retain its mycorrhizal relationship throughout its life. The above coral-root orchid seed (Corallorhiza) grows into a nonphotosynthetic mycotrophic wildflower that is completely dependent on its mycorrhizal fungus. Throughout its life, the orchid absorbs carbohydrates and minerals from its fungal partner, which in turn absorbs these vital nutrients from the roots of nearby forest trees. In a laboratory, orchid seeds can be grown in nutrient agar, like a sterile (axenic) culture of bacteria or fungal spores. The seed pod (capsule) of an unknown orchid containing many thousands of minute seeds. Each seed is enclosed in a cellular sheath (seed coat) resembling a short, silky hair. The seeds are dispersed into the wind like dust particles. In nature, the probability of an orchid seed finding a suitable place for germination and a compatible fungal partner are unlikely, so millions of seeds are released to increase the odds.  Bacterial Cell Larger Than An Orchid Seed  See Another Seed Capsule From An Orchid Table Of Relative Cell Sizes In Millimeters Fungus Flws In Forests (Coral Root Orchid) According to C.R. Gunn (World Guide To Tropical Drift Seeds and Fruits, 1976), the record for the largest seed embryo goes to Mora oleifera (Fabaceae), a large tree that grows in tidal marshlands and estuaries along the Pacific coast of tropical America. In Costa Rica, this tree often forms nearly pure stands just behind the mangrove swamps. Seeds of M. oleifera may be up to 7 inches (18 cm) long and up to 5 inches (8 cm) wide. Another species (M. excelsa) has slightly smaller seeds. Like other exalbuminous legume seeds, the two cotyledons comprise most of the seed. Since the cotyledons are part of the embryo, this species is certainly a strong contender for the record of world's largest seed. The seeds float in ocean current with their two large cotyledons connected or separate. Dried cotyledons washed up on beaches superficially resemble the shells of a bivalve mollusk. Seed of Mora oleifera showing the two large cotyledons. Since the cotyledons are technically part of the embryo, this is perhaps the largest embryo of any seed. Mora oleifera is a large tree that grows in tidal marshlands along the Pacific coast of tropical America. The seeds float in ocean water with their two large cotyledons connected or separate. Dried cotyledons that wash ashore on beaches superficially resemble the shells of a bivalve mollusk. See Cotyledons Of A Lima Bean Embryo See A Coconut Seed & Minute Embryo See Drift Seed (U) From Mora oleifera Provocative Seed Provocative seed and immature fruits of the Seychelles Island Palm (Lodoicea maldivica). Like the coconut (Cocos nucifera), the seed is enclosed by a thick, woody endocarp. The complete fruit (drupe) contains of an enormous, seed-bearing endocarp surrounded by a husk composed of a thin mesocarp and a smooth, outer exocarp. This is truly the largest seed produced by any plant on earth. 11. The World's Largest & Smallest Leaves. In addition to the largest seeds, palms also have the record for the largest leaves. The raffia palm (Raphia regalis) of tropical Africa has huge pinnate leaves up to 80 feet (24 m) long. The leaves of the Amazonian palm (Manicaria saccifera) are nearly 30 feet (8 m) long, and have been listed by some authors as the longest undivided leaf of any plant. However, according to Chuck Hubbuch of Fairchild Tropical Garden, Coral Gables, Florida, the leaf is typically divided shallowly at the tip and is not truly entire. The golf ball-sized fruits of Manicaria palms, called "sea coconuts," commonly wash ashore on beaches throughout the Caribbean and southern Florida. There are two additional palm candidates for the record of longest undivided leaf: Marojejya darianii, a palm native to Madagascar with a leaf up to 5 meters in length that is divided only once at the tip; and joey palm (Johannesteijsmannia altifrons), a palm native to Thailand with a leaf up to 4 meters long that is completely undivided. In the Private Life of Plants (BBC nature series), David Attenborough says "the giant arum of Borneo develops the biggest undivided leaf of all"--a surface area of 34 square feet. Without accurate dimensions for the Joey palm leaf, it is difficult to calculate its surface area; however, according to Internet images it appears to rival the size of the giant arum. Thanks to Eric Platt for bringing this to my attention. Circular floating leaves of the giant Amazonian water lily (Victoria amazonica) have a documented diameter of up to 2.4 meters (8 feet). Using the simple formula for the area of a circle (A = πr²), the largest leaves would have an area of 50 square feet. This is 47 percent larger than the leaf reported by David Attenborough. Giant Amazon water lily (Victoria amazonica), a member of the water lily family (Nyphaeaceae). The World's Smallest Leaves If you define a true leaf as a flattened, photosynthetic organ arising from the stem axis in vascular plants, then there are numerous contenders for the world's smallest leaf. Since mosses are nonvascular (without xylem tissue), they would generally be excluded from this record. Ferns are vascular plants, and the common water fern (Azolla filiculoides) has leaves that are only one mm in length. The minute California wildflower called pygmy weed (Crassula erecta) has minute fleshy leaves about 1.3 mm long. This is the diameter of the head of an ordinary straight pin. Many species in the cypress family (Cupressaceae) have overlapping scalelike leaves only 1-2 mm in length. This includes cypress (Cupressus), junipers (Juniperus), and cedars (Chamaecyparis and Thuja). Although the body of duckweeds has paired guard cells and stomata on its upper surface and superficially resembles a leaf (particularly the flattened duckweeds Spirodela, Landoltia and Lemna), it is morphologically and embryonically completely different. I prefer to call it a plant body rather than the term frond or thallus. The duckweed Spirodela polyrrhiza has a membranous, scalelike leaf (prophyllum) that envelops the dorsal and ventral surfaces of the basal end. This basal portion and its connecting stalk correspond to a condensed shoot that has become greatly reduced through evolution. In fact, more advanced members of the duckweed family, including Lemna, Wolffia and Wolffiella have lost this basal prophyllum altogether. In Spirodela polyrrhiza, one or more roots pass through the prophyllum on the underside of the plant body. The prophyllum is also visible on the underside of rootless, overwintering turions. Average turions are approximately 1/25th of an inch (1 mm) in length and 1-2 mm in width. The minute prophyllum is only about 1/75th to 1/50th of an inch (0.3 mm to 0.5 mm) in length. If the prophyllum is considered a greatly reduced leaf, then it is one of the smallest in the plant kingdom. Close-up view of the water fern (Azolloa filiculoides). The overlapping scalelike leaves (black arrow) are about 1/25th of an inch (1 mm) in length. Also shown in the photo are three species in the duckweed family (Lemnaceae): Wolffia borealis (1), W. columbiana (2) and Lemna minuta (3). Although the latter three species are very small, they do not have leaves. The Water Fern & Its Symbiotic Cyanobacteria Close-up view of a branchlet from the Oriental arborvitae (Thuja orientalis = Platycadus orientalis). Many species in the cypress family (Cupressaceae) have overlapping scalelike leaves only 1-2 mm in length. The white dots are stomata, minute pores each flanked by a pair of guard cells. Gas exchange with the atmosphere is accomplished through the stomata. Microscopic View Of Stomata & Guard Cells Left: Pygmy weed (Crassula erecta), a member of the stonecrop family (Crassulaceae). The minute leaf is about 1.3 mm long (the diameter of the head of an ordinary straight pin). Right: Turion of the duckweed Spirodela polyrrhiza, a member of the duckweed family (Lemnaceae). The turion is about 1.2 mm in width and 1.0 mm long. Note the minute, transparent, bractlike leaf called a prophyllum at the basal end. The prophyllum is only about 1/50th of an inch (0.5 mm) in width and 1/75th of an inch (0.3 mm) long. It overlaps both the dorsal and ventral sides of the turion, but is more visible on the lower (ventral) surface. The prophyllum of Landoltia punctata is much smaller and is truly microscopic. If the prophyllum is homologous to a leaf in its embryonic origin, then it is certainly should be recognized as one of the world's smallest leaves. See Images Of The duckweed Spirodela polyrrhiza Straight Pin & Sewing Needle Used In Wayne's Word Return To WAYNE'S WORD Home Page Return To NOTEWORTHY PLANTS Page Go To Biology GEE WHIZ TRIVIA Page Go To The LEMNACEAE ON-LINE Page All text material & images on these pages copyright © W.P. Armstrong