Botany in Popular Culture: The Tan Hua Flowers in Crazy Rich Asians

When a flower blooms, a celebration is in order. Flowers abound for much of the year, which means parties are called for pretty much non-stop (something Andrew W.K. would surely endorse). Since we can’t possibly celebrate every bloom, there are certain plants we have decided to pay more attention to – plants whose flowers aren’t so prolific, predictable, or long-lived; or plants whose flowers come infrequently or at odd times of the day (or night).

This is the case with the flowers of the night blooming cactus, Epiphyllum oxypetalum, which goes by many names including Dutchman’s pipe cactus, queen of the night, orchid cactus, night blooming cereus, and tan hua. Tan hua is the Chinese name for the plant, and this is how it is referred to in the book, Crazy Rich Asians by Kevin Kwan.

In the book, Nick Young brings his American girlfriend, Rachel Chu, to meet his ridiculously wealthy family in Singapore. Before the trip, Rachel was in the dark about the Young’s wealth. She first meets the family and their gargantuan mansion when Nick’s grandma, seeing that her tan hua flowers are about to bloom, throws an impromptu (and lavish) party. Nick refers to the flowers as “very rare,” blooming “extremely infrequently,” and “quite something to witness.”

In a seperate conversation, Nick’s cousin, Astrid, tries to convince her husband to attend the party by claiming, “it’s awfully good luck to see the flowers bloom.” Later, another one of Nick’s cousins tells Rachel, “it’s considered to be very auspicious to witness tan huas blooming.”

Tan hua (Epiphyllum oxypetalum) via wikimedia commons

Native to Mexico and Guatemala, E. oxypetalum was first brought to China in the 1600’s. Its beauty and intrigue along with its relative ease of cultivation helped it become popular and widespread across Asia and other parts of the world. Watching it bloom is considered a sacred experience by many, including in India, where it is said to bring luck and prosperity to households who are fortunate enough to see theirs bloom.

Epiphyllums are epiphytic, meaning they grow non-parasitically on the surfaces of other plants, such as in the crevices of bark or the crotches of branches. Like other cacti, they are essentially leafless, but their stems are broad, flat, and leaf-like in appearance. Showy, fragrant flowers are born along the margins of stems. The flowers of tan hua, as described in Crazy Rich Asians, appear as “pale reddish petals curled tightly like delicate fingers grasping a silken white peach.” A report (accompanied by photos) published by Sacred Heart University describes watching tan hua flowers progess from bud formation to full bloom, a process that took more than two weeks.

Tan huas are certainly not rare, as Nick described them. A number of Epiphyllum species and their hybrids are commonly cultivated; there is even an Epiphyllum Trail at San Diego Zoo’s Safari Park. Listed as “least concern” on the IUCN Red List, their popularity as ornamentals is noted but is not seen as affecting wild populations. Night blooming plants, while fascinating, aren’t all that rare either. Such plants have adapted relationships with creatures, like bats and moths, that are active during the night, employing their assistance with pollination. A paper published in Plant Systematics and Evolution describes the floral characteristics of Epiphyllum and similar genera: “The hawkmoth-flower syndrome, consisting of strongly-scented, night-blooming flowers with white or whitish perianths and long slender nectar-containing floral tubes is present in Cereus, Trichocereus, Selenicereus, Discocactus, Epiphyllum, and a number of other cactus genera.”

That being said, the specialness of a short-lived, infrequent, night blooming flower should not be understated, and really, parties being thrown in honor of any plant are something I can certainly get behind. Sitting in the courtyard late at night, the Young family and their guests watched as “the tightly rolled petals of the tan huas unfurled like a slow-motion movie to reveal a profusion of feathery white petals that kept expanding into an explosive sunburst pattern.” The look of it reminds Astrid of “a swan ruffling its wings, about to take flight.”

Later, “the tan huas began to wilt just as swiftly and mysteriously as they had bloomed, filling the night air with an intoxicating scent as they shriveled into spent lifeless petals.”

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Additional Resources:

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*Thank you Kathy for letting me borrow your Kindle so that I could write this post.

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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:

Phylogenetic Arts and Crafts

This is a guest post by Rachel Rodman.

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The foods we eat – namely fruits, vegetables, and grains – are all products of their own evolutionary stories. Some of the most well-known chapters in these stories are the most recent ones – dramatic changes in size and shape mediated by human selection.

One especially striking example is that of Brassica oleracea –the source of broccoli, cauliflower, kale, Brussels sprouts, kohlrabi, and cabbage. Each of these diverse vegetables belongs to the same species, and each is the product of a different kind of selection, exerted on different descendants of a common ancestor.

Corn is another famous chapter. The derivation of corn – with its thick cobs and juicy kernels developed from the ancestral grain teosinte, which it barely resembles – has been described as “arguably man’s first, and perhaps his greatest, feat of genetic engineering.”

But these, again, are recent chapters. Relatively. They unfolded over the course of consecutive human lifetimes –hundreds of years or thousands at the outset (sometimes much less). They are the final flourishes (for the moment) on a much older story — a story that significantly precedes agriculture as well as humans.

It is this older story that lies at the heart of truly deep differences, like those at play in the idiom “apples and oranges.” The contrast between these two fruits can be mapped according to many measures: taste, smell, texture, visual appearance, and so on. When used colloquially, the phrase serves as a proxy for unmanageable difference — to describe categories that differ along so many axes that they can no longer be meaningfully compared.

However, in evolutionary terms, the difference between apples and oranges is not ineffable. It is not a folksy aphorism or a Zen puzzle at which to throw up one’s hands. To the contrary, it can be temporalized and quantified; or at least estimated. In fact, in evolutionary terms, that difference comes down to about 100 million years. That is, at least, the date (give or take) when the last common ancestor of apples and oranges lived — a flowering plant from the mid-Cretaceous.

The best way to represent these deep stories is with a diagram called a phylogenetic tree. In a phylogenetic tree, each species is assigned its own line, and each of these lines is called a branch. Points at which two branches intersect represent the common ancestor of the species assigned to these branches.

Phylogenetic trees can serve many purposes. Their classical function is to communicate a hypothesis – a pattern of familial relationships supported by a particular set of data based on DNA sequence, fossils, or the physical characteristics of living organisms.

But here are two alternate reasons to build trees:

  • To inspire wonder
  • Or (my favorite) just because

To reflect these additional motivations – this conviction that trees are for everyone and for all occasions and that an evolutionary tree belongs on every street corner – when I build trees, I often avail myself of a range of non-traditional materials. I’ve written previously about creating edible trees using cake frosting and fruit, as well as building trees out of state symbols and popular songs. Now here are two additional building materials, which are arguably even more fun.

First: Stickers. This one is titled: “Like Apples and Oranges…and Bananas.”

Bananas split ways with the common ancestor of apples and oranges about 150 million years ago, 50 million years before the split between apples and oranges. On this tree, these relationships are represented like so: the banana branch diverges from the apple branch at a deeper position on the trunk, and the orange branch diverges from the apple branch at a shallower position. 

All of the data required to build this tree  (and essentially any tree) is available at TimeTree.orgOn TimeTree, select “Get Divergence Time For a Pair of Taxa” at the top of the page. This is where one can obtain a divergence time estimate for most pairs of species. The divergence time is an approximate date, millions of years ago, at which the organisms’ last common ancestors may have lived. For more heavy duty assistance, there is the “Load a List of Species” option at the bottom of the page. Here, one can upload a list of species names (.txt), and TimeTree will generate a complete tree – a schematic that can serve as a guide in patterning one’s own phylogenetic artwork.

Here, by way of additional illustration, are three more sticker trees, equally charming and equally mouthwatering:

Carrot, watermelon, broccoli, strawberry, and pear.

Onion, asparagus, tomato, cucumber, and cherry.

Raspberry, apricot, pea, grape, and green pepper.

Sticker trees are festive takes on traditional trees. They are brighter, livelier, and more lovely. But, like traditional trees, they are also 2D, restricted to a flat sheet of paper. To extend one’s phylogenetic art projects into three dimensions, one must modify the choice of materials. There are many options. The following 3D tree, for example, employs 13 pieces of plastic toy food, the accouterments of a typical play kitchen. Segments of yarn serve as branches.

Trees like these, made of stickers or toys, constitute playful takes on deep questions. In pencil and yarn, they sketch a network of primeval relationships. They tell the history of our foods, a narrative whose origins profoundly precede us, as well as our intention to selectively breed them. To the Way-Before, to the Way-Way-Way-Before, these projects give shape and color. If and where they succeed, it is because they manage to do two things at once: To communicate a vast biological saga extending across many millions of years, and to be completely cute. Perhaps best of all – and let it not go unmentioned – anyone can make them.

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Bio: Rachel Rodman has a Ph.D. in Arabidopsis genetics and presently aspires to recast all of art, literature, and popular culture in the form of a phylogenetic tree.

Book Review: A Feast of Weeds

Since I am planning on eating more weeds, it seems appropriate that I review this book. Not to be confused with Feast of Weeds, a series of apocalyptic novels about a world-ending plague, A Feast of Weeds, by Luigi Ballerini is tangentially about foraging and cooking wild, edible plants. I say “tangentially” because it’s not like other foraging guides. This is a “literary guide,” as the subtitle states, so in the place of plant descriptions and harvesting tips, etc. are verbose and erudite essays summarizing the various literary references that each of the species profiled has accumulated from antiquity to the modern era. Apart from dozens of recipes, the information presented in this book is more entertaining than it is practical; however, when telling the stories of plants, the human element is an important facet – particularly in the stories of edible and medicinal plants – and it is the human element that this book is concerned with.

Ballerini is an Italian poet, a cooking historian, and a professor of Italian literature at UCLA. The 31 plant species he chose to profile can all be foraged in Italy (most of them in one specific region), and all except for maybe capers can be found somewhere in the United States. The majority of the plants in this book are commonly cultivated as crops, ornamentals, or landscape plants – few are truly weeds – but all of them can be found growing wild somewhere. And that’s one of Ballerini’s main points – wild food and the act of foraging is a very different experience from farmed food and the act of buying it at the grocery store. Take arugula for example:

Try making a salad with arugula that you have gathered yourself in a field and compare its taste with what you have made a hundred times with pre-washed and sterilized arugula bought at the supermarket or even at a farmers’ market. It’s easy to predict the comment that will immediately come to your lips: ‘There’s no comparison.’

A selection of recipes accompanies each of the plants that Ballerini writes about. These recipes were “invented or elaborated” by Ada De Santis, who lives on a farm in the “heel of Italy” and who “enthusiastically agreed to divulge the secrets of her kitchen.” Ballerini partnered with De Santis because of her Italian ancestry and her vast experience with both wild and cultivated plants.

Each chapter in the book follows the same basic format: a discussion of the myriad references a certain plant has received in various writings throughout human history, an overview of the (often bizarre) medicinal uses the plant has had throughout the centuries, and a brief statement on when to harvest the plant. References include plays, poems, songs, myths, fiction and non-fiction, religious and sacred texts, medicinal plant guides, and even artwork. Reading through the book, my interest and attention waned often, partly due to Ballerini’s way of writing and also due to my lack of familiarity (and lack of interest, frankly) with the references. But there were enough interesting bits here and there that made it worth the effort.

common mallow (Malva neglecta )

Of course, my interest was mainly held by the chapters about the weeds. Apparently, mallow (Malva spp.) has been written about prolifically, leading Ballerini to write, “the history of mallow is complex and contradictory, rich in illustrious testimony but, given its effects, not always very noble.” Like other plants in the book, the medicinal uses for mallow have been so numerous that it could be considered “a true cure-all,” if in fact it truly treated all the things it has been claimed to treat. On a humorous note, Ballerini writes in the chapter on wild fennel (Foeniculum vulgare), “we have come to understand … if a plant is good for you, it is good for nearly everything – but particularly for snakebite.”

Ballerini especially enjoys sharing odd medical claims, like in the chapter about sow thistle (Sonchus oleraceus), in which Nicholas Culpepper promoted some interesting uses for its juice. Purportedly, bringing it to a boil or “warming it in some bitter almond oil inside the skin of a pomegranate is a sure remedy for deafness and tinnitus.” The medicinal uses of wild chicory (Cichorium intybus) are “as old as the hills,” with a medical papyri from ancient Egypt (circa 1550 B.C.) referencing its medicinal uses among “magic formulas and spells for driving away evil-intentioned demons.”

sow thistle (Sonchus sp.)

A couple of paragraphs about dandelion (Taraxacum officinale) find their way into the chapter about wild chicory. The rosettes of these two plants look similar, and the roots of both, when “roasted and ground, can be used as a substitute for coffee.” Dandelion is also known to be a diuretic, and is thus referred to as pisciailetto in Italy, pissenlit in France, and piss-a-beds in England.

Speaking of the names of things, how things came to be called what they are is a topic that Ballerini addresses frequently throughout the book. However, such origins aren’t always clear. In the chapter on wild raspberries (Rubus idaeus), Ballerini reflects on the “general uncertainty regarding the origin of the English term raspberry.” Does it originate from the Old French word rasper, the Spanish word raspar, and the Italian word raspare, all of which mean to rasp or to scrape? Ballerini laments, “this introduces very unpleasant connotations for such a delicate fruit (yet there are those who, when faced with roses always think of thorns).”

While the bulk of this book is of little use to me – I guess I’m just not that interested in classic literature or mythology – it’s worth keeping around for the recipes alone, several of which I am anxious to try. If the idea of an unconventional field guide appeals to you, this book might be up your alley, just as it apparently was for this reviewer.

Additional Book Reviews on Awkward Botany:

Eating Weeds: Lambsquarters

Last year during the Summer of Weeds I inadvertently wrote about several edible weeds, one of which I even ate. It’s not surprising that so many weeds are edible; there are plenty of plants out there – both native and introduced – that are, despite the fact that most of us stick with whatever is made available at the grocery store. Some edible weeds, dandelion included, were once commonly grown for food, while other weeds are close relatives of present day agricultural crops. The more I read about these things and the more my weeds obsession grows, the more I feel compelled to eat them (the edible ones, at least). Hence, a new series of posts: Eating Weeds.

I might as well start with an easy one. Chenopodium album, or lambsquarters, which I wrote about last summer, is a close relative of a number of common crops and a spitting image of quinoa. It happily grows alongside other plants in our vegetable gardens without even being asked to. It is highly nutritious and palatable – particularly the young leaves – and can be eaten raw or cooked. It is often compared to spinach and can be prepared and used in similar ways.

lambsquarters seedling (Chenopodium album)

For the purposes of this post, I decided to try lambsquarters pesto. While pesto is traditionally made using basil leaves, all kinds of other leaves – or combinations thereof – can be substituted. I have made pesto with parsley, which was interesting, as well as watercress, which was delicious. The possibilities are endless. So, why not lambsquarters?

Making pesto is incredibly simple. Blend together a combination of leaves, garlic, nuts or seeds, Parmesan cheese (or something similar), olive oil, salt, and pepper. Pine nuts are traditionally used to make pesto, but like the leaf component, a number of different nuts or seeds can be substituted. I rarely make pesto with pine nuts because, despite being delicious, they are pricey.

lambsquarters pesto

I made two batches of lambsquarters pesto. For the first I used walnuts, and for the second I used sunflower seeds. Both batches were delicious. How could they not be with all of that garlic and cheese in there? Lambsquarters is not a very bitter or strong-tasting green, so lambsquarters pesto might be perfect for anyone who is otherwise not fond of pesto (although that is a stance that I personally cannot fathom).

This is definitely something I will make again. I understand the frustration people have with lambsquarters. It can be prolific and hard to eliminate from a garden. Luckily, it makes an excellent pesto.

Resources:

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This series of posts was inspired in part by the book Dandelion Hunter, in which the author, Rebecca Lerner, attempts to go a full week eating only things she is able to forage in her hometown of Portland, Oregon. As you might imagine, many of the plants she forages are weeds.  

Spring Weeds in the Mustard Family

Is there a plant family that consists of more weedy species than the mustard family? Asteraceae and Poaceae, for sure. Fabaceae or Lamiaceae, perhaps. Regardless, Brassicaceae is replete with dozens of species – mostly annual – that are skilled at taking advantage of the disturbed environments that humans are in the habit of creating.

It helps that the mustard family is so large: 372 genera and over 4,000 species distributed across the globe. Around 55 genera are said to occur in North America. Most of the plants in this family are herbaceous; few are shrubs. Foliage is aromatic, especially when crushed. Flowers are particularly distinctive. Each flower has four petals – in some species petals are divided, giving the impression that there are more than four – arranged in the shape of a cross or “X.” Flowers are often small, have 4 tall stamens and 2 short stamens, and commonly come in white, yellow, pink, or purple. They are arranged on a raceme, which is typically either tall and straight or compact and flat-topped.

Fruits in the mustard family are capsules with two compartments separated by a clear membrane. The capsules may be at least three times longer than they are wide, in which case they are referred to as a silique; or they may be less than three times longer than they are wide and referred to as a silicle. This is a curious distinction, and it doesn’t tell you all that much. It’s more important to understand that the capsules of mustards can come in various sizes and shapes, and that some can be long and narrow while others are short and either round or angular.

mustard seeds via wikimedia commons

Despite the size or shape of the capsule, enclosed are numerous seeds – sometimes dozens. Surely one of the reasons why plants in the mustard family are so successful at proliferating is their ability to produce thousands, even tens of thousands, of seeds per plant. The seeds are typically tiny; and while they may not make it very far from the parent plant, they are numerous. Depending on the species, they can also remain viable for years, affording them the opportunity to sprout whenever conditions are right. You may have heard the biblical verse about faith the size of a mustard seed giving one the ability to move mountains. Size seems irrelevant here, so how about faith as tough, resilient, opportunistic, and resourceful as a mustard seed? If a mountain can be moved, mustards might be the one to do it.

While it isn’t the scope of this post, it’s worth mentioning the chemical compounds present in mustards that give them the flavors and health benefits we enjoy as well as the toxicity that can harm us and any other organisms that dare consume them. Glucosinolates, which are present in various concentrations depending on the species, are a defining characteristic of plants in the mustard family. They contribute to the spicy-ness of things like horseradish, radish, and condiment mustard while also acting as a natural insecticide, deterring herbivory.

And now on to the cast of characters:

Whitetop (Lepidium spp.)

Garlic mustard (Alliaria petiolata) – a noxious weed in many parts of North America – is fortunately not an issue in southwestern Idaho, otherwise it would be first on the list. Instead, we deal with whitetop – a noxious weed in Idaho and several other states. As the common name suggests, individual plants – up to two feet tall – are topped with a dense cluster of tiny, white flowers. Seed production in this group isn’t as abundant as other mustards; instead, the tour de force are their rhizomes. Whitetop is a perennial plant that spreads aggressively via underground stems as well as root fragments and can easily form expansive, dense patches, outcompeting other plants in the area.

Another common name for this group is hoary cress on account of their gray-green, fuzzy foliage. They are further distinguished by the shape of their seed pods: lens-podded hoary cress (L. chalepense), heart-podded hoary cress (L. draba), and globe-podded hoary cress (L. applelianum).

white top (Lepidium sp.)

white top (Lepidium sp.)

Tansymustard (Descurainia spp.)

There are two species of tansymustard (also known as flixweed) that occur in my part of the world, one is native and the other is introduced from Europe. They are indistinguishable to my untrained eye. If I have seen them side by side, I wouldn’t have known it. They are both annuals and can be as short as a few inches to over two feet tall. They have highly dissected, fern-like leaves and tiny, pale yellow or green-yellow flowers. The seed pods are very skinny and around an inch long. Each pod can hold 40 seeds, and a large plant can produce over 75,000 seeds. They are quick to take advantage of disturbed soil and come up in abundance after a fire. I’m not sure what it is about this year, but they have been particularly prolific this spring.

tansymustard (Descurainia sp.)

tansymustard (Descurainia sp.)

Blue Mustard (Chorispora tenella)

Also known as musk mustard or crossflower, this sticky, stinky, annual plant apparently makes cow’s milk taste funny; however some people still enjoy eating it. It can get to about a foot and a half tall, and is adorned with pretty, little, blue-purple flowers. The pointy seed pods split crosswise rather than lengthwise, an uncommon trait in mustards.

blue mustard (Chorispora tenella)

blue mustard (Chorispora tenella)

Desert Madwort (Alyssum desertorum)

Like tansymustard, this species is very similar in appearance to another closely related species, Alyssum alyssoides (commonly known as pale madwort or yellow alyssum). Both are annuals under a foot tall, covered in tiny hairs, with minuscule yellow flowers, and numerous round seed pods. They are adapted to dry, neglected sites.

yellow alyssum (Alyssum dessertorum)

Annual Honesty (Lunaria annua)

If you don’t recognize this plant when it’s flowering, you will when its seed pods ripen. They are thin, round discs up to three inches across. Eventually, the outer layers of the seed pods fall away, and translucent membranes remain, sometimes with seeds still attached. This trait has earned this species common names like money plant and silver dollar. The plants are attractive, reach up to three feet tall, and produce showy, purple flowers, which explains why they are popular ornamentals. However, like other mustards, the proficiency with which they reproduce in abundance via seeds, means they also easily migrate into natural areas and neglected sites.

annual honesty (Lunaria annua)

Hairy Bittercress (Cardamine hirsuta)

This little, quick-growing, fast-spreading annual is a common nuisance in greenhouses and nurseries. On stalks above compact rosettes are borne clusters of white flowers that, as Ken Thompson writes in The Book of Weeds, “are so tiny they are almost invisible.” The slender seed pods burst open at maturity, sending minuscule seeds flying. Brush your hand over a patch of mature hairy bittercress and you will be bombarded.

hairy bittercress (Cardamine hirsuta)

And the list goes on…

I’ve observed several other weedy species in this family recently, but to keep the length of this post reasonable I will just list them here: shepherd’s purse (Capsella bursa-pastoris), clasping pepperweed (Lepidium perfoliatum), spring draba (Draba verna), tumble mustard (Sisymbrium altissimum), and pennycress (Thlaspi arvense). This list only scracthes the surface; there are many other weeds in the mustard family. All deserve to be mentioned, so perhaps another time.

See Also: In Defense of Plants – One Mustard, Many Flavors