Winter Trees and Shrubs: Tulip Tree

At first glance, a tulip and a tulip tree couldn’t be more different. One is a bulb that puts out fleshy, green leaves in the spring, topped with colorful, cup-shaped flowers, barely reaching a foot or so tall. The other is a massive, deciduous tree with a broad, straight trunk that can grow to nearly 200 feet tall. But if you can get a look at the flowers, seed heads, and even the leaves of this enormous tree, you might see a resemblance – at least in the shape of these features – to one of our most popular spring flowering geophytes.

Tulip tree (Liriodendron tulipifera) is distributed across the eastern United States and has been planted widely outside of its native range. Also commonly known as tulip poplar, yellow poplar, and whitewood, it is a member of the magnolia family and is one of two species in its genus (the other being Liriodendron chinense – a tree found mainly in China). Many (if not most) deciduous trees of North America have small, inconspicuous flowers, but tulip trees – like its close relatives, the magnolias – have relatively large, showy flowers. The trouble is actually getting to see them since, at least on mature trees, they are borne in a canopy that is considerably taller than the average human.

Tulip tree flowers are cup-shaped, yellow-green and orange, with a series of prominent stamens surrounding the carpels which are attached to a long, slender receptacle giving it a cone-shaped appearance. As the flower matures into fruits, the tulip shape of the inflorescence is maintained as the seeds with their wing-like appendages form a tight, cone-like cluster that opens as the seeds reach maturity. The wings aid in dispersal as the seeds fall from the “cone” throughout the winter.

seed head of tulip tree (Liriodendron tulipifera)

The four-lobed leaves of tulip trees also form a vague tulip shape. They are alternately arranged, bright green, and up to five or six inches long and wide, turning yellow in the fall. Two prominent, oval-shaped stipules surround the stem at the base of the petiole of each leaf. These stipules come into play when identifying the leafless twigs of tulip trees during the winter months.

leaf of tulip tree (Liriodendron tulipifera) in late summer

The winter twigs of tulip trees are easily recognizable thanks to their duck bill shaped buds which are made up of two wine-red, violet, or greenish bud scales. The terminal buds are considerably larger and longer than the lateral buds, some of which are on little stalks. The twigs are smooth, olive-brown or red-brown, with just a few, scattered, white lenticels. Leaf scars are rounded with a dozen or so bundle scars that are either scattered or form an irregular ellipse. Pronounced stipule scars encircle the twig at the location of each leaf scar. Twigs can be cut lengthwise to reveal pale white pith that is separated by a series of diaphragms.

winter twig of tulip tree (Liriodendron tulipifera)
top right: the chambered pith of black walnut (Juglans nigra); bottom left: diaphragmed pith of tulip tree (Liriodendron tulipifera)

The bark of tulip trees can be easily confused with that of ash trees. Young bark is smooth and ash-gray to grayish green with pale, vertical cracks. As the tree matures, the cracks develop into furrows with flat-topped ridges. The ridges grow taller and more peaked, and the furrows grow deeper as the tree reaches maturity. In the book Winter Botany, William Trelease compares the mature bark of tulip trees to a series of parallel mountain ranges with deep gullies on either side.

maturing bark of tulip tree (Liriodendron tulipifera)

Perhaps even as tulips are blooming, the buds of tulip trees break to reveal their tulip-shaped, stipule bearing leaves. This makes for an interesting show. In The Book of Forest and Thicket, John Eastman describes it this way: “from terminal buds shaped like duck bills, successions of bills within bills uncurl and unfold, revealing a marvel of leaf packaging.”

More Winter Trees and Shrubs:


The photos of tulip tree were taken at Idaho Botanical Garden in Boise, Idaho.

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The Hidden Flowers of Viola

Violas keep a secret hidden below their foliage. Sometimes they even bury it shallowly in the soil near their roots. I suppose it’s not a secret really, just something out of sight. There isn’t a reason to show it off, after all. Showy flowers are showy for the sole purpose of attracting pollinators. If pollinators are unnecessary, there is no reason for showy flowers, or to even show your flowers at all. That’s the story behind the cleistogamous flowers of violas. They are a secret only because unless you know to look for them, you would have no idea they were there at all.

Cleistogamy means closed marriage, and it describes a self-pollinating flower whose petals remain sealed shut. The opposite of cleistogamy is chasmogamy (open marriage). Most of the flowers we are familiar with are chasmogamous. They open and expose their sex parts in order to allow for cross-pollination (self-pollination can also occur in such flowers). Violas have chasmogamous flowers too. They are the familiar five-petaled flowers raised up on slender stalks above the green foliage. Cross-pollination occurs in these flowers, and seed-bearing fruits are the result. Perhaps as a way to ensure reproduction, violas also produce cleistogamous flowers, buried below their leaves.

an illustration of the cleistogamous flower of Viola sylvatica opened to reveal its sex parts — via wikimedia commons

Flowers are expensive things to make, especially when the goal is to attract pollinators. Colorful petals, nectar, nutritious pollen, and other features that help advertise to potential pollinators all require significant resources. All this effort is worth it when it results in the ample production of viable seeds, but what if it doesn’t? Having a method for self-pollination ensures that reproduction will proceed in the absence of pollinators or in the event that floral visitors don’t get the job done. A downside, of course, is that a seed produced via self-pollination is essentially a clone of the parent plant. There will be no mixing of genes with other individuals. This isn’t necessarily bad, at least in the short term, but it has its downsides. A good strategy is a mixture of both cross- and self-pollination – a strategy that violas employ.

The cleistogamous flowers of violas generally appear in the summer or fall, after the chasmogamous flowers have done their thing. The fruits they form split open when mature and deposit their seeds directly below the parent plant. Some are also carried away by ants and dispersed to new locations. Seeds produced in these hidden flowers are generally superior and more abundant compared to those produced by their showy counterparts. People who find violas to be a troublesome lawn weed – expanding far and wide to the exclusion of turfgrass – have these hidden flowers to blame.

That being said, there is a defense for violas. In the book The Living Landscape by Rick Darke and Doug Tallamy, Tallamy writes: “Plants such as the common blue violet (Viola sororia), long dismissed by gardeners as a weed, can be reconstituted as desirable components of the herbaceous layer when their ecosystem functionality is re-evaluated. Violets are the sole larval food source for fritillary butterflies. Eliminating violets eliminates fritillaries, but finding ways to incorporate violets in garden design supports fritillaries.”

sweet violet (Viola odorata)

In my search for the cleistogamous flowers of viola, I dug up a sweet violet (Viola odorata). I was too late to catch it in bloom, but the product of its flowers – round, purple, fuzzy fruits – were revealed as I uprooted the plant. Some of the fruits were already opening, exposing shiny, light brown seeds with prominent, white elaiosomes, there to tempt ants into aiding in their dispersal. I may have missed getting to see what John Eastman calls “violet’s most important flowers,” but the product of these flowers was certainly worth the effort.

Fruits formed from the cleistogamous flowers of sweet violet (Viola odorata)

Up close and personal with the fruit of a cleistogamous flower

The seeds (elaiosomes included) produced by the cleistogamous flower of sweet violet (Viola odorata)

See Also:

Tea Time: Violet Leaf Tea

The genus Viola is large and widespread. Its flowers are easily recognizable and obviously popular. A significant number of Viola species, hybrids, and cultivars are commercially available and commonly planted in flower beds and container gardens. Certain species have even become weeds – vicious lawn invaders in some people’s opinion. Violets (or pansies in some cases) are also edible. Their leaves and/or flowers can be used in salads, drinks, and desserts. One way to use the leaves is to make tea, so that’s what I did.

I imagine you can make tea from any Viola species, but after some searching I found that two species frequently mentioned are Viola odorata and Viola sororia – two very similar looking plants, one from the Old World and the other from the New World.

sweet violet (Viola odorata)

Viola odorata – commonly known as sweet violet, wood violet, or English violet – is distributed across Europe and into Asia and has been widely introduced outside of its natural range. It has round, oval, or heart-shaped leaves with toothed margins that grow from the base of the plant, giving it a groundcover-type habit. Its flowers range from dark purple to white and are borne atop a single stem that curves downward at the top like a shepherd’s crook. It has no leafy, upright stems, and it spreads horizontally via stolons and rhizomes. The flowers are distinctly fragrant and have a long history of being used in perfumes.

One way to get a good whiff of these flowers is to try a trick described in the book The Reason for Flowers by Stephen Buchmann:

Go into a garden or any natural area and select one or more flowers you want to investigate…. Select a small, thoroughly washed and dried glass jar with a tight-fitting lid. Place just one type of flower in the jar. Set your jar in a warm, sunny place such as a windowsill and come back in an hour or two. Carefully open the lid and sniff…. If you’ve selected a blossom with even the faintest scent, you should be able to smell it now, since the fragrance molecules have concentrated inside the jar.

sweet violet flowers inside glass jar

Viola sororia – native to eastern North America –  is also commonly planted outside of its native range. It’s clearly a favorite, having earned the distinction of state flower in four U.S. states. Known as the common blue violet (or myriad other commons names), it looks and acts a lot like sweet violet. I distinguish them by their flowers, which are wider and rounder (chunkier, perhaps) than sweet violet flowers, and their leaves, which are generally more heart-shaped. Feel free to correct me. If, like me, you’re having trouble identifying violets, keep in mind that Viola species are highly variable and notorious hybridizers, so don’t beat yourself up over it. It’s their fault, not yours.

common blue violet (Viola sororia)

Violets bloom when the air is cool and the days are short. They are among the earliest plants to flower after the new year and among the latest plants flowering as the year comes to a close. In his entry on violets in The Book of Forest and Thicket, John Eastman refers to these early bloomers as “this low, blue flame in the woods.” They are like “a pilot light that ignites the entire burst of resurrection we call spring.” I can’t really picture spring without them. I find their unique flowers so intriguing that I fixate on them whenever I see them. And once I learned that I could make a tea out of their leaves, I had to try it.

I used the leaves of Viola odorata (or what I, with my amateur skills, identified as V. odorata). I picked several of what looked to be young leaves and left them to dry in the sun for several days. Later, I chopped them up and brewed a tea according to the instructions found on this website, which suggests using one tablespoon of dried leaves in sixteen ounces of water. Apparently, a little goes a long way, and I probably could have used fewer leaves than I did.

dried, chopped up leaves of sweet violet (Viola odorata) for making tea

The tea has a nice green color and smells a bit like grass to me. It may even taste like grass. I found it fairly bitter. Sierra didn’t like it and called it musty. I enjoyed it, but would likely enjoy it more if I hadn’t made it quite so strong. The aforementioned website also recommends combining violet leaf with other things like mint, dandelion, clover, and/or chamomile. I imagine a combination of ingredients could be better than just violet leaf on its own. Another site warns that “some of the wild violets have an unpleasant soapy flavor,” so that’s something to keep in mind when selecting your leaves for tea and other things. Either way, violet leaf tea is an experience worth having.

See Also: Pine Needle Teas

Eating Weeds: Dandelion Flowers

Mention weeds, and the first plant most of us think of is dandelion. It is essentially the poster child when it comes to weeds and one of the few weeds that entire books have been written about. Its notoriety partly comes from being so ubiquitous and recognizable, but it also comes from its utility. It has a long history of being used medicinally and culinarily, and, surprising to some I’m sure, is still grown agriculturally today.

Dandelion is an attractive and useful plant whose main offense is being so accomplished and proficient at staying alive, reproducing, and moving itself around. The principal thing it gets accused of is invading our lawns. With its brightly colored flowers on tall stalks and its globe of feathery seeds, it makes itself obvious, unlike other lawn invaders that tend to blend in more. Once it makes itself at home, it refuses to leave, adding to the frustration. Consider the vats of herbicide that have been applied to turf grass in an attempt to wipe out dandelions. The fact that they hang around, taunting those who care about that sort of thing, helps explain why they are so hated.

common dandelion (Taraxacum officinale)

As Ken Thompson writes in The Book of Weeds, dandelions are “too familiar to need describing,” and since there is already so much written about them, I don’t feel the need to write much myself. Below, instead, are a few excerpts from a handful of books that discuss them.

“It seems many of us possess a conscious will not to believe anything good about this remarkable harbinger of spring which, by its ubiquity and persistance, make it the most recognized and most hated of all ‘weeds.'” — The Dandelion Celebration by Peter Gail

“Dandelion heads consist entirely of overlapping ray florets. … Each floret has its own male and female organs, the (female) style surmounting the (male) stamens. Stamens are unnecessary, however, for the plant to produce seed; much, if not most dandelion seed reproduction occurs asexually (apomixis), without pollen fertilization or any genetic involvement of male cells. But insect pollination (each floret produces abundant nectar in its tubular base) and self-pollination, plus vegetative reproduction via sprouting of new plants from roots and root fragments, also occurs – so this plant has all reproductive fronts covered, surely an important reason for its wide abundance and distribution.” — The Book of Field and Roadside by John Eastman

“Wild violets are too limp and their flowers to insipidly small, too prone to damp, dark corners, as if lacking upright amour propre; in contrast, dandelions are too lush and healthy, their vigorous, indestructible roots, gaudy flowers, and too-plentiful seed heads all too easily spawned with their easygoing means of reproduction by parachute-like seeds, landing where they will, suggesting something of human sexual profligacy.” — Weeds by Nina Edwards

Charles Voysey “The Furrow” (© Victoria and Albert Museum, London

“Dandelions demonstrate evolution in action on suburban lawns. Over several seasons of mowing, the only dandelions that can flower are short-stemmed plants that duck the blade. Mowing thus becomes a selective factor, and in time most of the yard’s surviving dandelion flowers hug the ground.” — The Book of Field and Roadside by John Eastman

“When you stop seeing them as villains, many weeds can be considered as useful plants and certainly have been in the past. Dandelions produce fresh, green leaves nearly all year round. They make a nice addition to a salad, although most people find them too bitter to eat in any quantity. … Dandelion roots are edible too, and have been used in the past as a coffee substitute. If you can find some nice fat burdock roots to go with them, you could even make your own old-fashioned dandelion and burdock drink.” — The Alternative Kitchen Garden by Emma Cooper

“Early medieval Arabian physicians recognized the medicinal properties of dandelion, recorded in Egyptian tombs and described by Theophrastus. Its diuretic effects are mirrored in the common names of pissabed and the French pissenlit; it is recommended for the liver, kidneys, and gallbladder, and even for the treatment of diabetes. In India it is also a traditional remedy for snakebites and its milky sap is said to cure surface tumors and warts, and even unsightly moles and freckles.” — Weeds by Nina Edwards

I ate dandelion flowers blended up with eggs and cooked like scrambled eggs. Its a simple recipe that I adapted from instructions found in the The Dandelion Celebration by Peter Gail. The flowers taste more or less the way they smell. They have a bitterness to them that is akin to their leaves but isn’t nearly as strong. I have eaten dandelion leaves several times and I like them, so the bitterness doesn’t really bother me. If I were to make this again I would use a higher egg to dandelion flower ratio, because even though I enjoyed the flavor, it was a little strong.

Eating Weeds: Clovers

If you ever spent time hunting for four-leaf clovers in the lawn as a kid, in all likelihood you were seeking out the leaves of Trifolium repens or one of its close relatives. Commonly known as white clover, the seeds of T. repens once came standard in turfgrass seed mixes and was a welcome component of a healthy lawn thanks to its ability to fix atmospheric nitrogen and provide free fertilizer. But around the middle of the 20th century, when synthetic fertilizers and herbicides became all the rage, clover’s reputation shifted from acceptable to disreputable. Elizabeth Kolbert, in an article in The New Yorker about American lawns, recounts the introduction of the broadleaf herbicide 2,4-D: “Regrettably, 2,4-D killed not only dandelions but also plants that were beneficial to lawns, like nitrogen-fixing clover. To cover up this loss, any plant that the chemical eradicated was redefined as an enemy.”

white clover (Trifolium repens) in turf grass

This particular enemy originated in Europe but can now be found around the globe. It has been introduced both intentionally and accidentally. Commonly cultivated as a forage crop for livestock, its seeds can be found hitchhiking to new locations in hay and manure. Clover honey is highly favored, and so clover fields are maintained for honey production as well. Its usefulness, however, doesn’t protect it from being designated as a weed. In Weeds of North America, white clover is accused of being “a serious weed in lawns, waste areas, and abandoned fields.”

White clover is a low-growing, perennial plant that spreads vegetatively as well as by seed. It sends out horizontal shoots called stolons that form roots at various points along their length, creating a dense groundcover. Its compound leaves are made up of three, oval leaflets, and its flower heads are globe-shaped and composed of up to 100 white to (sometimes) pink florets. Rich in nectar, the flowers of white clover draw in throngs of bees which assist in pollination. Closely related and similar looking strawberry clover, Trifolium fragiferum, is distinguished by its pink flowers and its fuzzy, rounded seed heads that resemble strawberries or raspberries. Red clover, T. pratense, grows more upright and taller than white and strawberry clovers and has red to purple flowers.

leaves and seed heads of strawberry clover (Trifolium fragiferum)

Clovers are tough plants, tolerating heat, cold, drought, and trampling. Lawns deprived of water go brown fairly quickly, revealing green islands of interlopers, like clover, able to hang in there throughout dry spells. These days, many of us are reconsidering our need for a lawn. Lawns are water hogs that require a fair amount of inputs to keep them green and free of weeds, pests, and diseases. The excessive amounts of fertilizers and pesticides dumped on them from year to year is particularly troubling.

Along with our reconsideration of the lawn has come clover’s return to popularity, and turfgrass seed mixes featuring clover are making a comeback. To keep clover around, herbicde use must be curbed, and so lawns may become havens for weeds once more. Luckily, many of those weeds, including clover, are edible, so urban foragers need only to step out their front door to find ingredients for their next meal.

The leaves and flowers of clover can be eaten cooked or raw. Fresh, new leaves are better raw than older leaves. That being said, clover is not likely to be anyone’s favorite green. Green Deane refers to it as a “survival or famine food” adding that “only the blossoms are truly pleasant to human tastes,” while “the leaves are an acquired or tolerated taste.” In The Book of Field and Roadside, John Eastman remarks: “As humanly edible herbs, clovers do not rank as choice. Yet they are high in protein and vitamins and can be eaten as a salad or cooked greens and in flower head teas. Flower heads and leaves are much more easily digested after boiling.”

I tried strawberry clover leaves and flower heads in a soup made from a recipe found in the The Front Yard Forager by Melany Vorass Herrara. Around two cups of clover chopped, cooked, and blended with potatoes, scallions, and garlic in vegetable or chicken broth is a fine way to enjoy this plant. I don’t anticipate eating clover with great frequency, partly because it is included in a list of wild edible plants with toxic compounds in The North American Guide to Common Poisonous Plants and Mushrooms and also because I have to agree with the opinions of the authors quoted above – there are better tasting green things. Either way, it’s worth trying at least once.

clover soup

More Eating Weeds Posts on Awkward Botany:

When Milkweed Kills

When you think of milkweed, you probably think of the life it supports. The monarch butterfly, for one. As the sole food source for its leaf-eating larvae, monarchs would be a thing of the past if milkweeds disappeared. Numerous other insects feed on its foliage as well, and there are a plethora of organisms that feed on its nectar, including bees, butterflies, beetles, wasps, and other insects, as well as hummingbirds. And speaking of birds, some birds use the silky hairs attached to the seeds to line their nests, while other birds strip stringy fibers from the stems for nest building. And while it is not a major food source for mammals, deer and other animals have been known to sample it. Indeed, milkweed is a veritable life force.

red milkweed beetle (Tetraopes sp.) feeds on milkweed

But it’s also a poisonous plant. The latex sap of milkweed contains cardiac glycosides, among a variety of other toxic chemicals. The plant produces these chemicals to defend itself from herbivory, and so the insects that feed on it have adapted a variety of strategies to avoid being poisoned. Some bite a hole in a leaf vein and wait for the milky sap to drain before proceeding to eat the leaf. Others are able to consume the toxic foliage without being poisoned by it. Some even store the toxic chemicals in their bodies, making themselves poisonous to other organisms that dare consume them.

Aphids on Mexican whorled milkweed (Asclepias fascicularis). One species commonly found on milkweed is the oleander aphid (Aphis nerii), an introduced species that feeds on milkweeds and other plants in the dogbane family.

While milkweed is generally found to be unpalatable to most livestock, those that venture to eat it risk being poisoned and even killed. A guide to milkweed written by the Xerces Society states, “sheep and goats are the most likely to be poisoned because they are browsers and often prefer to feed on weeds over other forages.” Weeds of the West calls Utah milkweed (Asclepias labriformis) “the most poisonous of all western milkweeds,” claiming that “as little as one ounce of green leaf material … can kill an adult sheep.” It also lists swamp milkweed (Asclepias incarnata) as “suspected of causing livestock deaths.” To make matters worse, dead and dried milkweed plants retain their toxicity, which is a problem when they end up in animal feed.

Despite their toxicity, humans have been consuming milkweed for centuries. Young shoots and leaves can be eaten after boiling them several times, refreshing the water each time, and a medicinal tea can be made from the roots. While fatal poisonings of humans haven’t been reported, Nancy Turner and Patrick von Aderkas warn in their book The North American Guide to Common Poisonous Plants and Mushrooms that “uncooked shoots and the mature plants should never be consumed”

But milkweed’s toxic sap is not its only method for killing.

In fact, it may not even be its most deadly. And this is where things get interesting. Last month I arrived at work one morning to find a portion of a dried-up milkweed inflorescence on my desk that had been left there by a friend and co-worker. Stuck to the inflorescence were three, dead, dried-up honey bees, their legs trapped in the slotted hoods of the flowers. Apparently this is a common occurrence; one that is mentioned in nearly every resource about milkweeds that I have read now, and yet I had never heard of it nor seen it until this gift was left for me. I then went out to a patch of milkweed to see this for myself. Sure enough, I found a few dead bees trapped in the flowers of showy milkweed.

dead honey bee stuck in the flowers of showy milkweed (Asclepias speciosa)

Milkweed flowers do not always give up their pollen sacs easily. The slits where the pollinia are found can, on occasion, trap the legs of visiting insects. John Eastman describes this in The Book of Field and Roadside, “insects sometimes become permanently wedged as the fissures trap their feet or the pollinia entangle them, and they die hanging from the flowers.” While milkweed species are native to North America, honey bees are not; they have not evolved alongside the flowers of milkweed, yet they are drawn in, like so many other insects, to the nutritious and abundant nectar.

Native or not, honey bees are not the only insects getting trapped in the flowers. Eastman reports seeing various species of butterflies ensnared as well, and a paper by S.W. Frost lists cluster flies, soldier beetles, and a couple species of moths as unsuspecting victims of these unruly flowers. Frost goes on to observe that, “in spite of the hazards,” bees, wasps, and various other insects “visited the flowers of milkweeds freely.”

In a paper published in 1887, Charles Robertson describes the insect visitors of several different milkweed species. He found an occassional dead insect on the flowers of swamp milkweed, adding that “this occurs only when all or most of the feet are entangled simultaneously, so as to render the insect absolutely helpless.” Observing common milkweed (Asclepias syriaca), Robertson finds that “even when small and short-legged insects succeed in extracting pollinia and inserting them into the stigmatic chambers, they have great difficulty in breaking the retinacula, and often lose their lives in consequence.”

Honey bees were easily the most common victims observed in Robertson’s study, leading him to quip, “it seems that the flowers are better adapted to kill [honey bees] than to produce fruit through their aid.” And a honey bee’s trouble doesn’t always end when she escapes the grasp of the flowers. Pollinia and its connecting tissues can get so tangled around her legs and other body parts that she can no longer forage, subjecting herself to starvation and predation.

To add insult to injury, dead and dying insects stuck to flowers result in another interesting phenomenon. Robertson writes, “many fall prey to predacious insects. I have seen them while still alive, attacked by ants, spiders and [predatory stink bugs].” Eastman adds daddy longlegs to the list of “scavengers” or “cleanup specialists” that come to feed on “flower trapped insects.” As it turns out, visiting the flowers of milkweed can be a dangerous, even deadly, game.

See Also: Idaho’s Native Milkweeds

Tiny Plants: Duckweeds

Obviously, a series about tiny plants must begin with duckweeds – a group of aquatic plants that holds records in a number of categories including smallest flowering plants, smallest vascular plants, and smallest fruits. They are so small, in fact, that they don’t even have true stems or leaves, but rather are composed of undifferentiated vegetative tissue known as a thallus. Some species have one or a few tiny rootlets; others form no roots at all. However, what they lack in their hyper-diminutive size, they make up for in their ability to form massive colonies, creating dense mats that can take up serious square footage in a pond or lake. Depending on the species present, a single square yard of a duckweed colony can contain hundreds of thousands of individual plants.

Five genera make up the duckweed subfamily (Lemnoideae): Spirodela, Lemna, Landoltia, Wolffia, and Wolffiella. This group used to be considered the family Lemnaceae, but has since been placed in Araceae – the arum family. While they are considered flowering plants, not all species of duckweeds produce flowers, and those that do, do so only rarely. They mainly reproduce asexually through a process called budding, in which growth occurs at the base of the thallus (or frond) and eventually splits off from the parent plant. This process happens fairly quickly, which is why duckweeds are able to create substantial colonies.

 

Duckweed mats form atop the still waters of lakes and ponds, but can also form in very slow moving rivers and streams. Their presence is an indicator of high levels of minerals and nutrients, which is why they are commonly seen in agricultural and industrial wastewater ponds. Nutrients are absorbed through the underside of the thallus, so the rootlets of duckweeds likely function more for stabilization than for nutrient uptake. As duckweed mats expand and grow dense, they shade the environments below them. John Eastman writes about this phenomenon in The Book of Swamp and Bog: “Thick blankets of duckweed can shade pond bottoms, preventing adequate photosynthesis and making life difficult or impossible for submersed plants and animals…however, this is often a problem of only intermittent duration.” One potential benefit of such dense mats is that they can kill off mosquito larvae. Eastman points out that for this to be the case, the duckweed may need to be accompanied by other surface dwelling plants in order to create dense enough shade.

duckweed 1

Duckweeds overwinter by forming turions, small buds that act as storage organs. Eastman explains the process:

These tiny, kidney-shaped buds detach and immediately sink to the bottom, where they remain all winter. In the spring, each turion expels a gas bubble, which causes it to rise to the surface, where it rapidly develops into a new duckweed thallus. Turion formation requires a combination of bright sunlight and high water temperature.

Duckweeds colonize new areas either by moving downstream (if they have that option) or by finding themselves attached to the fur, feathers, or feet of animals that unwittingly transport them. The common name, duckweed, is likely derived from the fact that it is a major source of food for waterfowl. It is high in protein and rich in nutrients, especially when you factor in all the tiny critters growing on and among it. Muskrats and beavers occasionally eat duckweeds as well. Despite losses from herbivory by these creatures, being made mobile by their moving bodies is a major boon.

A collection of various duckweed species - photo credit: wikimedia commons

A collection of various duckweed species – photo credit: wikimedia commons

Duckweeds are also consumed by various species of fish, which is why they are commonly used as a food source in aquaculture. Frogs and other amphibians as well as various aquatic insects and microinvertebrates also consume duckweeds. The diversity of small animals and protists that use duckweeds and the environments they help create is incredible. Eastman writes:

Duckweed mats host a large variety of small fauna that feed, lay eggs, or shelter amid the plants. Many of them secure themselves to the thallus rootlets or undersides, where they snare and capture passing food organisms or particles. Protozoans, rotifers, insect larvae, and crustaceans are often abundant.

Humans have also been known to eat duckweeds. Duckweed farming is not a simple procedure, but a highly nutritious food source is the result when it can be done. A simpler alternative is to use the harvest as animal feed. Duckweeds are also used in bioremediation and are being considered as a source of biofuel.

Depending on the species, an individual duckweed can vary in width from 10 millimeters to less than 1 millimeter. They truly are tiny wonders of the plant world, and it is worth getting down to their level for a closer look (hand lens recommended).

Additional Resources

Ethnobotany: Cattails

“If you ever eat cattails, be sure to cook them well, otherwise the fibers are tough and they take more chewing to get the starchy food from them than they are worth. However, they taste like potatoes after you have been eating them for a couple weeks, and to my way of thinking are extremely good.”  – Sam Gribley in My Side of the Mountain by Jean Craighead George

franz

Illustration by Franz Anthony (www.franzanth.com)

Ask anyone to list plants commonly found in American wetlands, and you can guarantee that cattails will make the list nearly every time. Cattails are widespread throughout the Northern Hemisphere. They are so successful, that it is hard to picture a wetland without them. In her book, Braiding Sweetgrass, Robin Wall Kimmerer discusses this well known association:

Cattails grow in nearly all types of wetlands, wherever there is adequate sun, plentiful nutrients, and soggy ground. Midway between land and water, freshwater marshes are among the most highly productive ecosystems on earth, rivaling the tropical rainforest. People valued the supermarket of the swamp for the cattails, but also as a rich source of fish and game. Fish spawn in the shallows; frogs and salamanders abound. Waterfowl nest here in the safety of the dense sward, and migratory birds seek out cattail marshes for sanctuary on their journeys.

The two most abundant species of cattails in North America are Typha latifolia (common cattail) and Typha angustifolia (narrow leaf cattail). T. angustifolia may have been introduced from Europe. The two species also hybridize to form Typha x glauca. There are about 30 species in the genus Typha, and they share the family Typhaceae with just one other genus. The common names for cattail are nearly as abundant as the plant itself: candlewick, water sausage, corn dog plant, cossack asparagus, reedmace, nailrod, cumbungi, etc., etc.

Cattails have long, upright, blade-like leaves. As they approach the base of the plant, the leaves wrap around each other to form a tight bundle with no apparent stem. As Kimmerer puts it, this arrangement enables the plants to “withstand wind and wave action” because “the collective is strong.” Flowers appear on a tall stalk that reaches up towards the tops of the leaves. The inflorescence is composed of hundreds of separate male and female flowers. Male flowers are produced at the top of the stalk and female flowers are found directly below them. In the spring, the male flowers dump pollen down onto the female flowers, and wind carries excess pollen to nearby plants, producing what looks like yellow smoke.

After pollination, the male flowers fade away, leaving the female flowers to mature into a seed head. Just like the flowers, the seeds are small and held tightly together, maintaining the familiar sausage shape. Each seed has a tuft of “hair” attached to it to aid in wind dispersal. In The Book of Swamp and Bog, John Eastman writes about the abundant seeds (“an estimated average of 220,000 seeds per spike”) of cattail: “A quick experiment, one that Thoreau delighted to perform, demonstrates how tightly the dry seeds are packed in the spike – pull out a small tuft and watch it immediately expand to fill your hand with a downy mass.”

cattails bunch

cattail fluff

Because cattails spread so readily via rhizomes, prolific airborne seeds mostly serve to colonize new sites, away from the thick mass of already established cattails. The ability to dominate vast expanses of shoreline gives cattails an invasive quality that often results in attempts at removal. Various human activities may be aiding their success. Regardless, they provide food and habitat to numerous species of insects, spiders, birds, and mammals. A cattail marsh may not be diverse plant-wise, but it is teeming with all sorts of other life.

Ethnobotanically speaking, it is hard to find many other species that have as many human uses as cattails. For starters, nearly every part of the plant is edible at some point during the year. The rhizomes can be consumed year-round but are best from fall to early spring. They can be roasted, boiled, grated, ground, or dried and milled into flour. Starch collected from pounding and boiling the rhizomes can be used as a thickener. In the spring, young shoots emerging from the rhizomes and the tender core of the leaf bundles can be eaten raw or cooked and taste similar to cucumber. Young flower stalks can be boiled and eaten like corn on the cob and taste similar to artichoke. Pollen, which is high in protein, can be mixed with flour and used to make pancakes and baked goods, among other things. The seeds can be ground into flour or pressed to produce cooking oil.

Cattail leaves can be used to make cords, mats, baskets, thatch, and many other things. Kimmerer writes about the excellent wigwam walls and sleeping mats that weaved cattail leaves make:

The cattails have made a suburb material for shelter in leaves that are long, water-repellent, and packed with closed-cell foam for insulation. … In dry weather, the leaves shrink apart from one another and let the breeze waft between them for ventilation. When the rains come, they swell and close the gap, making the [wall] waterproof. Cattails also make fine sleeping mats. The wax keeps away moisture from the ground and the aerenchyma provide cushioning and insulation.

The fluffy seeds make great tinder for starting fires, as well as excellent insulation and pillow and mattress stuffing. The dry flower stalks can be dipped in fat, lit on fire, and used as a torch. Native Americans used crushed rhizomes as a poultice to treat burns, cuts, sores, etc. A clear gel is found between the tightly bound leaves of cattail. Kimmerer writes, “The cattails make the gel as a defense against microbes and to keep the leaf bases moist when water levels drop.” The gel can be used like aloe vera gel to soothe sunburned skin.

Eastman rattles off a number of commercial uses for cattail: “Flour and cornstarch from rhizomes, ethyl alcohol from the fermented flour, burlap and caulking from rhizome fibers, adhesive from the stems, insulation from the downy spikes, oil from the seeds, rayon from cattail pulp, …” To conclude his section on cattails he writes, “With cattails present, one need not starve, freeze, remain untreated for injury, or want for playthings.”

Additional Resources:

Ethnobotany: White Man’s Foot, part two

Earlier this year, as part of the ethnobotany series, I wrote about plantains (Plantago spp.), of which at least one species is commonly referred to as white man’s foot (or some version of that). Since writing that post, I happened upon a couple of other sources that had interesting and informative things to say about plantains. Rather than go back and update the original post, I decided to make a part two. Hopefully, you find this as interesting as I do. If nothing else, the sources themselves are worth checking out for the additional, fascinating information they contain about all sorts of plants.

plantago_boise capitol building

From The Book of Field and Roadside by John Eastman

Concerning their cosmopolitan nature: “Although both plantains [P. major and P. lanceolata] are Eurasian natives, they have long been thoroughly naturalized global residents; the designation ‘alien’ applies to them in the same sense that all white and black Americans are alien residents.”

In which I learned a new term: “Both species are anthropophilic (associate with humans); they frequent roadsides, parking areas, driveways, and vacant lots, occurring almost everywhere in disturbed ground. Where one species grows, the other can often be found nearby.”

Medicinal and culinary uses according to Eastman: “Plantains have versatile curative as well as culinary properties; nobody need go hungry or untreated for sores where plantains grow. These plants contain an abundance of beta carotene, calcium, potassium, and ascorbic acid. Cure-all claims for common plantain’s beneficial medical uses include a leaf tea for coughs, diarrhea, dysentery, lung and stomach disorders, and the root tea as a mouthwash for toothache. … Their most frequent and demonstrably effective use as a modern herb remedy, however, is as a leaf poultice for insect bites and stings plus other skin irritations. The leaf’s antimicrobial properties reduce inflammation, and its astringent chemistry relieves itching, swelling, and soreness.”

Even the seeds are “therapeutic”: “The gelatinous mucilage surrounding seeds can be readily separated, has been used as a substitute for linseed oil. Its widest usage is in laxative products for providing bulk and soluble fiber called psyllium, mainly derived from the plantain species P. ovata and leafy-stemmed plantain (P. psyllium), both Mediterranean natives.”

Plantain’s “cure-all reputation continues” today: Claims range from a homeopathic cancer remedy to a stop-smoking aid, “supposedly causing tobacco aversion.”

Claims of the healing properties of plantains abound in literature: “John the Baptist, in the lore of the saints, used it as a healing herb; Anglo Saxon gardeners called it the ‘mother of herbs.’ Plantain is ‘in the command of Venus and cures the head by antipathy to Mars,’ according to 17th century English herbalist-astrologist Nicholas Culpeper. Plantains also bear frequent mention in the works of Chaucer and Shakespeare.”

The worst thing plantains have to offer according to Eastman: “the airborne pollen they shed in large amounts, contributing to many hay fever allergies.”

Illustration by Amelia Hansen from The Book of Field and Roadside by John Eastman

Illustration by Amelia Hansen from The Book of Field and Roadside by John Eastman

From Weeds: In Defense of Nature’s Most Unloved Plants by Richard Mabey

Mabey’s too-good-to-paraphrase overview of plantain: “Plantain, ‘the mother or worts,’ is present in almost all the early prescriptions of magical herbs, back as far as the earliest Celtic fire ceremonies. It isn’t clear why such a drab plant – a plain rosette of grey-green leaves topped by a flower spike like a rat’s-tail – should have had pre-eminent status. But its weediness, in the sense of its willingness to tolerate human company, may have had a lot to do with it. The Anglo-Saxon names ‘Waybroad’ or ‘Waybread’ simply mean ‘a broad-leaved herb which grows by the wayside.’ This is plantain’s defining habit and habitat. It thrives on roadways, field-paths, church steps. In the most literal sense it dogs human footsteps. Its tough, elastic leaves, growing flush with the ground, are resilient to treading. You can walk on them, scuff them, even drive over them, and they go on living. They seem to actively prosper from stamping, as more delicate plants around them are crushed. The principles of sympathetic magic, therefore, indicated that plantain would be effective for crushing and tearing injuries. (And so it is, to a certain extent. The leaves contain a high proportion of tannins, which help to close wounds and halt bleeding.)”

On the inclusion of plantains in Midsummer’s Eve rituals: “On Midsummer’s Eve, great bonfires were lit in the countryside, and bundles of wild herbs thrown on them. Most of the plants were agricultural weeds, including St. John’s-wort, corn marigold, corn poppy, mayweed, mugwort, ragwort, plantain, and vervain.”

More about Midsummer’s Eve and the “future-foretelling powers” of this “divination herb, stretching sight into the future”: “On Midsummer’s Eve in Berwickshire, the flowering stems were employed by young women in a charm which would predict whether they would fall in love. It was a delicate, almost erotic process in which the sexual organs of the plantain were used as symbolic indicators. Two of the ‘rat’s-tail’ flowering spikes were picked, and any visible purple anthers removed. The two spikes were wrapped in a dock leaf and placed under a stone. If, by the next day, more anthers had risen erect from the flowering spikes, loves was imminent.”

"Greater - or 'ratstail' - plantain had by this time been nicknamed 'Englishman's foot' by the Native Americans, who had witnessed its prodigious advance in the white man's wake." - Richard Mabey, Weeds: In Defense of Nature's Most Unwanted Plants

“Greater – or ‘ratstail’ – plantain had by this time been nicknamed ‘Englishman’s foot’ by the Native Americans, who had witnessed its prodigious advance in the white man’s wake.” – Richard Mabey, Weeds: In Defense of Nature’s Most Unwanted Plants

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