Asteraceae

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Meet Erigeron linearis

Erigeron is a genus of herbaceous, flowering plants consisting of between 390 and 460 species and is a member of the aster/sunflower family (Asteraceae). Plants in this genus are annuals, biennials, or perennials and are mainly found in temperate regions around the world. At least 163 species occur in the contiguous United States. Erigeron diversity is particularly high in western states; however, each state is home to at least one Erigeron species.

A common name for plants in this genus is fleabane. This name comes from an outdated belief that the plants can be used to repel or poison fleas, flies, gnats, and other tiny insects, a belief for which there is no evidence. In Ancient Greek, the name Erigeron is said to mean something akin to “old man in the early morning,” likely referring to the appearance of the seed heads which look like little tufts of white hair. Some Erigeron species are also commonly referred to as daisies.

desert yellow fleabane (Erigeron linearis)

One species of Erigeron that I would like you to meet is Erigeron linearis. While most of the plants in this genus have flowers that are white, pink, or various shades of purple, E. linearis is a yellow-flowered species, hence the common name, desert yellow fleabane. Another common name for this plant is narrow leaved fleabane, a reference to its linear leaves. E. linearis is a small plant with a prominent taproot that reaches up to 20 centimeters tall and forms a leafy, rounded mat or cushion of whitish or gray-green, alternately arranged leaves. The white appearance is due to numerous, fine, appressed hairs on the leaves and stems. Flower stalks are produced in abundance in late spring through early summer and are mostly leafless. They reach above the mound of leaves and are each topped with at least one flower head, which nods at first, but then straightens out as the flowers open. Each flower head is about 2 centimeters wide and is typical of plants in the sunflower family, with a cluster of deep yellow disc florets in the center, surrounded by ray florets that are lighter in color. Both disc and ray florets are fertile; however, the disc florets have both “male” (stamens) and “female” (pistils) flower parts, while the ray florets have only “female” parts. The involucre, which sits at the base of the flowers, is egg-shaped or hemispheric and made up of a series of tiny, fuzzy bracts called phyllaries.

the flower head of desert yellow fleabane (Erigeron linearis)

The fruit of Erigeron linearis is called a cypsela, an achene-like fruit that is characteristic of plants in the sunflower family. The fruits are miniscule and topped with a pappus composed of short outer bristles and longer, pale, inner bristles. The two types of pappus bristles (or double pappus) must be the reason for the scientific name this species was originally given in 1834, Diplopappus linearis. While the seeds of more than 80% of flowering plant species found in dryland regions exhibit some form of dormancy, a study published in Plant Biology (2019), found that E. linearis is one of the few species with non-dormant seeds. This means that for those of us interested in growing plants native to the Intermountain West, E. linearis is a pretty easy one to grow and is a great addition to water-wise gardens, pollinator gardens, and rock gardens.

Erigeron linearis seedling

Erigeron linearis is distributed across several western states and into Canada. It is found in northern California, eastern Oregon and Washington, southern British Columbia, across Idaho and east into southern Montana, western Wyoming and northwestern Utah. It is found at low to moderate elevations in open, rocky foothills, grasslands, sagebrush steppe, and juniper woodlands. It prefers well-drained soils and full sun. It is one of many interesting plants found on lithosols (also known as orthents), which are shallow, poorly develop soils consisting of partially weathered rock fragments. In the book Sagebrush Country, Ronald Taylor calls lithosols “the rock gardens of the sagebrush steppe,” and refers to E. linearis and other members of its genus as “some of the more colorful components of the lithosol gardens.” E. linearis is a food source for pronghorn, mule deer, and greater sage-grouse, and the flowers are visited by several species of bees and butterflies. The plant is also a larval host for sagebrush checkerspots.

desert yellow fleabane (Erigeron linearis)

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Flowers Growing Out of Flowers (Things Are Getting Weird Out There)

I’m sure that anyone living through the events of 2020 would agree, these are truly wild times. So, when I stumbled across some purple coneflowers that appeared to be growing flowers out of flowers, I thought to myself, “Of course! Why not!?!” The world is upside down. Anything is possible.

As it turns out, however, this phenomenon occurs more frequently than I was aware. But it’s not necessarily a good thing, particularly if you’re concerned about plant health. We’ll get to that in a minute. First, what’s going on with these flowers?

Flowers in the aster family are unique. They have the appearance of being a single flower but are actually a cluster of two types of much smaller flowers all packed in together. Purple coneflower (Echinacea purpurea) is a great example of this. Its flower heads are composed of dozens of disc flowers surrounded by a series of ray flowers. The minuscule disc flowers form the cone-like center of the inflorescence. The petals that surround the cone are individual ray flowers. This tight cluster of many small flowers (or florets) is known as a composite. Sunflowers are another example of this type of inflorescence.

Flowers are distinct organs. Not only are they the reproductive structures of flowering plants, but unlike the rest of the plant, they exhibit determinate growth. Flowers are, after all, plant shoots that have been “told” to stop growing like other shoots and instead modify themselves into reproductive organs and other associated structures. Unlike other shoots, which continue to grow (or at least have the potential to), a flower (and the fruit it produces) is the end result for this reproductive shoot. This is what is meant by determinate growth. However, sometimes things go awry, and the modified shoots and leaves that make up a flower don’t develop as expected, producing some bizarre looking structures as a result.

An example of this is a double flower. Plants with double flowers have mutations in their genes that cause disruptions during floral development. This means that their stamens and carpels (the reproductive organs of the flowers) don’t develop properly. Instead, they become additional petals or flowers, resulting in a flower composed of petals upon petals upon petals – a look that some people like, but that have virtually nothing to offer the pollinators that typically visit them. Because of their ornamental value, double-flowered varieties of numerous species – including purple coneflower – can be found in the horticultural trade.

double-flowered purple coneflower

Genetic mutations are one way that odd looking flowers come about. It is not the cause, however, of the freak flowers that I recently came across. What I witnessed was something called phyllody and was the result of an infection most likely introduced to the plant by a leafhopper or some other sap-sucking insect. Phyllody, which has a variety of causes, is a disruption in plant hormones that leads to leaves growing in place of flower parts. As a result, the flowers become sterile and green in color. In the case of purple coneflower, leafy structures are produced atop shoots arising from the middle of ray and/or disc florets. In other species, shoots aren’t visible and instead the inflorescence is just a cluster of leaves. In a sense, the reproductive shoot has returned to indeterminate growth, having switched back to shoot and leaf production.

Phyllody can have either biotic or abiotic causes. Biotic meaning infection by plant pathogens – including certain viruses, bacteria, and fungi – or damage by insects. Abiotic factors like hot weather and lack of water can result in a temporary case of phyllody in some plants. Phyllody plus a number of other symptoms made it clear that the purple coneflower I encountered had a fairly common disease known as aster yellows. This condition is caused by a bacterial parasite called a phytoplasma, and is introduced to the plant via a sap-sucking insect. It then spreads throughout the plant, infecting all parts. The phyllody was a dead give away, but even the flowers that weren’t alien-looking were discolored. The typical vibrant purple of the ray flowers was instead a faded pink color. The flowers that had advanced phyllody – along with the rest of the plant – were turning yellow-green.

This inflorescence isn’t exhibiting phyllody yet, but the purple color in the ray flowers is quickly fading.

Hundreds of plant species are susceptible to aster yellows, and not just those in the aster family. Once a plant is infected with aster yellows, it has it for good and will never grow or reproduce properly. For this reason, it is best to remove infected plants from the garden to avoid spreading the infection to other plants. As cool as the flowers may look, infected plants just aren’t worth saving.

Further Reading: 

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Eating Weeds: Chicory

Over the course of human history, plant species once esteemed or considered useful have been recategorized into something less desirable. For one reason or another, plants fall out of favor or wear out their welcome, and, in come cases, are found to be downright obnoxious, ultimately losing their place in our yards and gardens. The particularly troublesome ones are branded as weeds, and put on our “do not plant” lists. These plants are not only unfavored, they’re despised. But being distinguished as a weed doesn’t necessary negate a plant’s usefulness. It’s likely that the plant still has some redeeming characteristics. We’ve just chosen instead to pay more attention its less redeeming ones.

Chicory is a good example of a plant like this. At one point in time, Cichorium intybus had a more prominent place in our gardens, right alongside dandelions in fact. European colonizers first introduced chicory to North America in the late 1700’s. Its leaves were harvested for use as a salad green and its roots were used to make a coffee additive or substitute. Before that, cultivation of chicory for these and other purposes had been going on across Europe for thousands of years, and it still goes on today to a certain extent. Along with other chicory varieties, a red-leafed form known as radicchio and a close cousin known as endive (Chicorium endivia) are grown as specialty crops, occassionally finding their way into our fanciest of salads.

Radicchio di Chioggia (Cichorium intybus var. foliosum) is a cultivated variety of chicory. (via wikimedia commons)

Chicory’s tough, adaptable nature and proclivity to escape cultivation have helped it become widespread, making itself at home in natural areas as well as urban and rural settings. Its perennial life history helps make it a fixture in the landscape. It sends down a long, sturdy taproot and settles in for the long haul. It tolerates dry, compacted soils with poor fertility and doesn’t shy away from roadside soils frequently scoured with salts. It’s as though it was designed to be a city weed.

Unlike many other perennial weeds, chicory doesn’t spread vegetatively. It starts its life as a seed, blown in from a nearby plant. After sprouting, it forms a dandelion-esque rosette of leaves during its first year. Wiry, branched stems rise up from the rosette in following years, reaching heights of anywhere from about a foot to 5 or 6 feet. When broken, leaves, stems, and roots ooze a milky sap. Abundant flowers form along the gangly stems. Like other plants in the aster family, each flower head is composed of multiple flowers. Chicory flower heads are all ray flowers, lacking the disc flowers found in the center of other plants in this family. The petals are a brilliant blue – sometimes pink or white. Individual flowers last less than a day and are largely pollinated by bees. The fruits lack the large pappus found on dandelions and other close relatives, but the seeds are still dispersed readily with the help of wind, animals, and human activity.

chicory (Cichorium intybus) via wikimedia commons

The most commonly consumed portions of chicory are its leaves and roots. Its flowers and flower buds are also edible. Young leaves and blanched leaves are favored because they are the least bitter. Excluding the leaves from light by burying or covering them up keeps them pale and reduces their bitter flavor. This is standard practice in the commercial production of certain chicory varieties. The taproots of chicory are dried, roasted, and ground for use as a coffee substitute. They are also harvested commercially for use as a natural sweetener due to their high concentration of inulin.

my puny chicory root

I harvested a single puny chicory root in order to make tea. On my bike ride to work there is a small, sad patch of chicory growing in the shade of large trees along the bike path. I was only able to pull one plant up by the roots. The others snapped off at the base. So, I took my tiny root, dried and roasted it in the oven, and ground it up in a coffee grinder. I followed instructions for roasting found on this website, but there are many other sources out there. I had just enough to make one small cup of tea, which reminded me of dandelion root teas I have had. Sierra found it to be very bitter, and I agreed but still enjoyed it. I figure that wild plants, especially those growing in stressful conditions like mine was, are likely to be more bitter and strong tasting compared to coddled, cultivated ones found in a garden.

roasted chicory root

roasted and ground chicory root

When I find a larger patch of feral chicory, I hope to try one of several recipes included in Luigi Ballerini’s book, A Feast of Weeds, as well as other recipes out there. I’ll be sure to let you know how it goes.

Are you curious to know how chicory became such a successful weed in North America? Check out this report in Ecology and Evolution to learn about the genetic explanation behind chicory’s success.

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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.

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The Agents That Shape the Floral Traits of Sunflowers

Flowers come in a wide array of shapes, sizes, colors, and scents. Their diversity is downright astounding. Each individual species of flowering plant has its own lengthy story to tell detailing how it came to look and act the way it does. This is its evolutionary history. Unraveling this history is a nearly insurmountable task, but one that scientists continue to chip away at piece by piece.

In the case of floral traits – particularly for flowers that rely on pollinators to produce seeds – it is safe to say that millennia of interactions with floral visitors have helped shape not only the way the flower looks, but also the nature of its nectar and pollen. However, flowers are “expensive” to make and maintain, so even though they are necessary for reproduction, plants must find a balance between that and allocating resources for defense – against both herbivory and disease – and growth. This balance can differ depending on a plant’s life history – whether it is annual or perennial. An annual plant has one shot at reproduction, so it can afford to funnel much of its energy there. If a perennial is unsuccessful at reproduction one year, there is always next year, as long as it has allocated sufficient resources towards staying alive.

Where a plant exists in the world also influences how it looks. Abiotic factors like temperature, soil type, nutrient availability, sun exposure, and precipitation patterns help shape, through natural selection, many aspects of a plant’s anatomy and physiology, including the structure and composition of its flowers. Additional biotic agents like nectar robbers, florivores, and pathogens can also influence certain floral traits.

This is the background that researchers from the University of Central Florida and University of Georgia drew from when they set out to investigate the reasons for the diverse floral morphologies in the genus Helianthus. Commonly known as sunflowers, Helianthus is a familiar genus consisting of more than 50 species, most of which are found across North America. The genus includes both annuals and perennials, and all but one species rely on cross-pollination to produce viable seeds. Pollination is mainly carried out by generalist bees.

Maximilian sunflower (Helianthus maximiliani)

Helianthus species are found in diverse habitats, including deserts, wetlands, prairies, rock outcrops, and sand dunes. Their inflorescences – characteristic of plants in the family Asteraceae – consist of a collection of small disc florets surrounded by a series of ray florets, which as a unit are casually referred to as a single flower. In Helianthus, ray florets are completely sterile and serve only to attract pollinators. Producing large and numerous ray florets takes resources away from the production of fertile disc florets, and sunflower species vary in the amount of resources they allocate for each floret form.

In a paper published in the July 2017 issue of Plant Ecology and Evolution, researchers selected 27 Helianthus species and one Phoebanthus species (a closely related genus) to investigate “the evolution of floral trait variation” by examining “the role of environmental variation, plant life history, and flowering phenology.” Seeds from multiple populations of each species were obtained, with populations being carefully selected so that there would be representations of each species from across their geographic ranges. The seeds were then grown out in a controlled environment, and a series of morphological and physiological data were recorded for the flowers of each plant. Climate data and soil characteristics were obtained for each of the population sites, and flowering period for each species was collected from various sources.

The researchers found “all floral traits” of the sunflower species to be “highly evolutionarily labile.” Flower size was found to be larger in regions with greater soil fertility, consistent with the resource-cost hypothesis which “predicts that larger and more conspicuous flowers should be selected against in resource-poor environments.” However, larger flower size had also repeatedly evolved in drier environments, which goes against this prediction. Apart from producing smaller flowers in dry habitats, flowering plants have other strategies to conserve water such as opening their flowers at night or flowering for a short period of time. Sunflowers do neither of these things. As the researchers state, “this inconsistency warrants consideration.”

The researchers speculate that “the evolution of larger flowers in drier environments” may be a result of fewer pollinators in these habitats “strongly favoring larger display sizes in self-incompatible species.” The flowers are big because they have to attract a limited number of pollinating insects. Conversely, flowers may be smaller in wetter environments because there is greater risk of pests and diseases. This is supported by the enemy-escape hypothesis – smaller flowers are predicted in places where there is increased potential for florivory and pathogens. Researchers found that lower disc water content had also evolved in wetter environments, which supports the idea that the plants may be defending themselves against flower-eating pests.

Seed heads of Maximilian sunflower (Helianthus maximiliani)

Another interesting finding is that, unlike other genera, annual and perennial sunflower species allocate a similar amount of resources towards reproduction. On average, flower size was not found to be different between annual and perennial species. Perhaps annuals instead produce more flowers compared to perennials, or maybe they flower for longer periods. This is something the researchers did not investigate.

Finally, abiotic factors were not found to have any influence on the relative investment of ray to disc florets or the color of disc florets. Variations in these traits may be influenced instead by pollinators, the “biotic factor” that is considered “the classic driver of floral evolution.” This is something that will require further investigation. As the researchers conclude, “determining the exact drivers of floral trait evolution is a complex endeavor;” however, their study found “reasonable support for the role of aridity and soil fertility in the evolution of floral size and water content.” Yet another important piece to the puzzle as we learn to tell the evolutionary history of sunflowers.

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When Sunflowers Follow the Sun

Tropisms are widely studied biological phenomena that involve the growth of an organism in response to environmental stimuli. Phototropism is the growth and development of plants in response to light. Heliotropism, a specific form of phototropism, describes growth in response to the sun. Discussions of heliotropism frequently include sunflowers and their ability to “track the sun.” This conjures up images of a field of sunflowers in full bloom following the sun across the sky. However cool this might sound, it simply doesn’t happen. Young sunflowers, before they bloom, track the sun. At maturity and in bloom, the plants hold still.

What is happening in these plants is still pretty cool though, and a report published in an August 2016 issue of Science sheds some light on the heliotropic movements of young sunflowers. They begin the morning facing east. As the sun progresses across the sky, the plants follow, ending the evening facing west. Over night, they reorient themselves to face east again. As they reach maturity, this movement slows, and most of the flowers bloom facing east. Over a series of experiments, researchers were able to determine the cellular and genetic mechanisms involved in this spectacular instance of solar tracking.

Helianthus annuus (common sunflower) is a native of North America, sharing this distinction with dozens of other members of this recognizable genus. It is commonly cultivated for its edible seeds (and the oil produced from them) as well as for its ornamental value. It is a highly variable species and hybridizes readily. Wild populations often cross with cultivated ones, and in many instances the common sunflower is considered a pesky weed. Whether crop, wildflower, or weed, its phototropic movements are easy to detect, making it an excellent subject of study.

Researchers began by tying plants to stakes so that they couldn’t move. Other plants were grown in pots and turned to face west in the morning. The growth of these plants was significantly stunted compared to plants that were not manipulated in these ways, suggesting that solar tracking promotes growth.

The researchers wondered if a circadian system was involved in the movements, and so they took sunflowers that had been growing in pots in a field and placed them indoors beneath a fixed overhead light source. For several days, the plants continued their east to west and back again movements. Over time, the movements became less detectable. This and other experiments led the researchers to conclude that a “circadian clock guides solar tracking in sunflowers.”

Another series of experiments helped the researchers determine what was happening at a cellular level that was causing the eastern side of the stem to grow during the day and the western side to grow during the night. Gene expression and growth hormone levels differed on either side of the stem depending on what time of day it was. In an online article published by University of California Berkeley, Andy Fell summarizes the findings: “[T]here appear to be two growth mechanisms at work in the sunflower stem. The first sets a basic rate of growth for the plant, based on available light. The second, controlled by the circadian clock and influenced by the direction of light, causes the stem to grow more on one side than another, and therefore sway east to west during the day.”

The researchers observed that as the plants reach maturity, they move towards the west less and less. This results in most of the flowers opening in an eastward facing direction. This led them to ask if this behavior offers any sort of ecological advantage. Because flowers are warmer when they are facing the sun, they wondered if they might see an increase in pollinator visits during morning hours on flowers facing east versus those facing west. Indeed, they did: “pollinators visited east-facing heads fivefold more often than west-facing heads.” When west-facing flowers where warmed with a heater in the morning, they received more pollinator visits than west-facing flowers that were not artificially warmed, “albeit [still] fewer than east-facing flowers.” However, increased pollinator visits may be only part of the story, so further investigations are necessary.

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I’m writing a book about weeds, and you can help. For more information, check out my Weeds Poll.

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Summer of Weeds: Salsify

Picking a favorite weed is challenging. If we dismiss entirely the idea that a person is not supposed to like weeds, the challenge is not that “favorite weeds” is an oxymoron; it is, instead, that it is impossibile to pick one weed among hundreds of weeds that is the most attractive, the most impressive, the most useful, the most forgiving, whatever. For me, salsify is a top contender.

Salsify and goatsbeard are two of several common names for plants in the genus Tragopogon. At least three species in this genus have been introduced to North America from Europe and Asia. All are now common weeds, widespread across the continent. All have, at some point, been cultivated intentionally for their edible roots and leaves, but Tragopogon porrifolius – commonly known as oyster plant or purple salsify – may be the only one that is intentionally grown in gardens today. Its purple flowers make it easy to determine between the other two species, which have yellow flowers.

As it turns out, I am not familiar with purple salsify. I don’t think it is as common in western North America as it is in other parts of the continent. In fact, the most common of the three in my corner of the world appears to be Tragopogon dubius, commonly known as western salsify. Tragopogon pratensis (meadow salsify) makes an appearance, but perhaps not as frequently. To complicate matters, hybridization is common in the genus, so it may be difficult to tell exactly what you are looking at.

western salsify (Tragopogon dubius)

Regardless, salsify is a fairly easy weed to identify. It is a biennial (sometimes annual, sometimes perennial) plant that starts out as a rosette of gray-green leaves that are grass-like in appearance. Eventually a flower stalk emerges, adorned with more grass-like leaves, branching out to form around a half dozen flower heads. Salsify is in the aster family, in which flower heads typically consist of a tight grouping of disc and ray florets. In this case, only ray florets are produced. The florets are yellow or lemon-yellow, and each flower head sits atop a series of pointed bracts which encase the flower (and the forming seed head) when closed. Examining the length of the bracts is one way to tell T. dubius (bracts extend beyond the petals) from T. pratensis (bracts and petals are equal in length).

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

The flowers of salsify open early in the morning and face the rising sun. By noon, they have usually closed. This phenomenon is the reason behind other common names like noonflower and Jack-go-to-bed-at-noon. Salsify’s timely flowering makes an appearance in Elizabeth Gilbert’s novel, The Signature of All Things: “Alma learned to tell time by the opening and closing of flowers. At five 0’clock in the morning, she noticed, the goatsbeard petals always unfolded. … At noon, the goatsbeard closed.”

The seed heads of salsify look like over-sized dandelions. Each seed (a.k.a. achene) is equipped with a formidable pappus, and with the help of a gust of wind, seeds can be dispersed hundreds of feet from the parent plant. The seeds don’t remain viable for very long, but with each plant producing a few hundred seeds and dispersing them far and wide, it is not hard to see why salsify has staying power.

Open, sunny areas are preferred by salsify, but it can grow in a variety of conditions. In The Book of Field and Roadside, John Eastman writes, “goatsbeards can establish themselves in bare soil, amid grasses and old-field vegetation, and in heavy ground litter; such adaptability permits them to thrive across a range of early plant successional stages.” Wild Urban Plants of the Northeast lists the following sites as “habitat prefrences” of meadow salsify: “abandoned grasslands, urban meadows, vacant lots, rubble dumps, and at the base of rock outcrops and stone walls.” While generally not considered a noxious weed, Tragopogon species are commonly encountered and widely naturalized. Last summer on a field trip to Mud Springs Ridge near Hells Canyon, salsify was one of only a small handful of introduced plants I observed looking right at home with the native flora.

Seed heads of western salsify (Tragopogon dubius) before opening

All that being said, why is salsify one of my favorite weeds? Its simple and elegant form appeals to me. Its gray- or blue-green stems and leaves together with its unique, yellow flowers are particularly attractive to me. And its giant, globe-shaped seed heads, which seem to glisten in the sun, captivate me. Its not a difficult weed to get rid off. It generally pulls out pretty easily, and it’s a satisfying feeling when you can get it by the root. It’s a sneaky weed, popping up full grown inside of another plant and towering above it, making you wonder how you could have missed such an intrusion. The roots are said to be the most palatable before the plant flowers, so if you can spot the young rosette – disguised as grass and also edible – consider yourself lucky. I haven’t tried them yet, but I will. [Editor’s note: Sierra tells me that I have eaten them in a salad she made, but at the time I didn’t know they were in there so I don’t remember what they tasted like.] If they are any good, that will be one more reason why salsify is one of my favorite weeds.

Bonus excerpt from Emma Cooper’s book, Jade Pearls and Alien Eyeballs, regarding Tragopogon porrifolius:

Salsify is often called the vegetable oyster, because its roots are supposed to have an oyster-like flavor although I suspect nobody would be fooled. The long roots are pale and a bit like carrots – they are mild and sweet and when young can be eaten raw. Mature roots are better cooked. Traditionally a winter food, any roots left in the ground in spring will produce a flush of edible foliage.

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Summer of Weeds: Pineapple Weed

“The spread of the fruitily perfumed pineapple weed, which arrived in Britain from Oregon in 1871, exactly tracked the adoption of the treaded motor tyre, to which its ribbed seeds clung as if they were the soles of small climbing boots.” – Richard Mabey, Weeds: In Defense of Nature’s Most Unloved Plants

Can a plant that is native to North America be considered a weed in North America? Sure. If it is acting “weedy” according to whatever definition we decide to assign to the word, then why not? Can “weeds” from North America invade Europe the same way that so many “weeds” from there have invaded here? Of course! Pineapple weed is just one such example.

Native to western North America and northeastern Asia, this diminutive but tough annual plant in the aster family can now be found around the globe. Matricaria discoidea gets its common name from the distinctive fruity scent it gives off when its leaves and flowers are crushed. Its scent is not deceptive, as it is yet another edible weed (see Eat the Weeds). Teas made from its leaves have historically been used to treat upset stomachs, colds, fevers, and other ailments.

pineapple weed (Matricaria discoidea)

Pineapple weed reaches as few as a couple centimeters to a little over a foot tall. Its leaves are finely divided and fern-like in appearance. Its flower heads are cone or egg-shaped, yellow-green, and cupped in light-colored, papery bracts. The flower heads lack ray florets and are composed purely of tightly packed disc florets. The fruits (i.e. seeds) are tiny, ribbed achenes that lack a pappus.

Compacted soils are no match for pineapple weed. It is often seen growing in hard-packed roadways and through small cracks in pavement, and it is undeterred by regular trampling. It is a master of disturbed sites and is commonly found in home gardens and agriculture fields. It flowers throughout the summer and is often confused with mayweed (Anthemis cotula); the telltale difference is that mayweed gives off a foul odor when crushed.

Meriwether Lewis collected pineapple weed along the Clearwater River during the Lewis and Clark Expedition. In their book, Lewis and Clark’s Green World, Scott Earle and James Reveal write, “There is nothing in the expedition’s journals about the plant, but it would seem that there was little reason for Lewis to collect the two specimens that he brought back other than for its ‘agreeable sweet scent.’ It is otherwise an unremarkable, rayless member of the aster family.” The authors continue their mild ribbing with this statement: “The pineapple weed deserves its appellation, for it is a common weed – although a relatively innocuous one – that grows in disturbed places, along roadsides, and as an unwanted garden guest.”

pineapple weed (Matricaria discoidea) – photo credit: wikimedia commons

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Quote of the Week:

From Weeds and What They Tell (ed. 1970) by Ehrenfried Pfeiffer

“Weeds are WEEDS only from our human egotistical point of view, because they grow where we do not want them. In Nature, however, they play an important and interesting role. They resist conditions which cultivated plants cannot resist, such as drought, acidity of soil, lack of humus, mineral deficiencies, as well as a one-sidedness of minerals, etc. They are witness of [humanity’s] failure to master the soil, and they grow abundantly wherever [humans] have ‘missed the train’ – they only indicate our errors and Nature’s corrections. Weeds want to tell a story – they are natures way of teaching [us] – and their story is interesting. If we would only listen to it we could apprehend a great deal of the finer forces through which Nature helps and heals and balances and, sometimes, also has fun with us.”

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Drought Tolerant Plants: Pearly Everlasting

Despite being such a widely distributed and commonly occurring plant, Anaphalis margaritacea is, in many other ways, an uncommon species. Its native range spans North America from coast to coast, reaching up into Canada and down into parts of Mexico. It is found in nearly every state in the United States, and it even occurs throughout northeast Asia. Apart from that, it is cultivated in many other parts of the world and is “weedy” in Europe. Its cosmopolitan nature is due in part to its preference for sunny, dry, well-drained sites, making it a common inhabitant of open fields, roadsides, sandy dunes, rocky slopes, disturbed sites, and waste places.

Its common name, pearly everlasting, refers to its unique inflorescence. Clusters of small, rounded flower heads occur in a corymb. “Pearly” refers to the collection of white bracts, or involucre, that surround each flower head. Inside the bracts are groupings of yellow to brown disc florets. The florets are unisexual, which is unusual for plants in the aster family. Plants either produce all male flowers or all female flowers (although some female plants occasionally produce florets with male parts). Due to the persistent bracts, the inflorescences remain intact even after the plant has produced seed. This quality has made them a popular feature in floral arrangements and explains the other half of the common name, “everlasting.” In fact, even in full bloom, the inflorescences can have a dried look to them.

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Pearly everlasting grows from 1 to 3 feet tall. Flowers are borne on top of straight stems that are adorned with narrow, alternately arranged, lance-shaped leaves. Stems and leaves are gray-green to white. Stems and undersides of leaves are thickly covered in very small hairs. Apart from contributing to its drought tolerance, this woolly covering deters insects and other animals from consuming its foliage. In The Book of Field and Roadside, John Eastman writes, “Insect foliage feeders are not numerous on this plant, owing to its protective downy ‘gloss.’ … The plant’s defensive coat seems to prevent spittlebug feeding on stem and underleaves. The tomentum also discourages ant climbers and nectar robbers.”

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Not all insects are thwarted however, as Anaphalis is a host to the caterpillars of at least two species of painted lady butterflies (Vanessa virginiensis and V. cardui). Its flowers, which occur throughout the summer and into the fall. are visited by a spectrum of butterflies, moths, bees, and flies.

Because the plants produce either male or female flowers, cross-pollination between plants is necessary for seed development. However, plants also reproduce asexually via rhizomes. Extensive patches of pearly everlasting can be formed this way. Over time, sections of the clonal patch can become isolated from the mother plant, allowing the plant to expand its range even in times when pollinators are lacking.

The attractive foliage and unique flowers are reason enough to include this plant in your dry garden. The flowers have been said to look like eye balls, fried eggs, or even, as Eastman writes, “white nests with a central yellow clutch of eggs spilling out.” However you decide to describe it, this is a tough and beautiful plant deserving of a place in the landscape.

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Photos in this post are of Anaphalis margaritacea ‘Neuschnee’ and were taken at Idaho Botanical Garden in Boise, Idaho.

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The Nippleworts of Camassia Natural Area

This is a guest post. Words and illustration by Mesquite Cervino.

At the end of a residential neighborhood that is barely off the 205 in the hills of West Linn, Oregon is a small, 26 acre preserve called the Camassia Natural Area. The defining features of the landscape were caused by the Missoula Floods (aka the Spokane or Bretz floods) at the end of the last ice age (12 to 19 thousand years ago) which swept away the already established soil and in their place deposited glacial erratics from other far-away places, some even coming all the way from Canada. The flood reached eastern Oregon and the Willamette via the Columbia River Gorge and created the green and rocky plateau that is now Camassia.

While the reserve is named after a widespread plant in the park, which is a common camas (Camassia quamash) that blooms in April and early May, the park has over 300 different species overall. However, one species in particular has kicked in the door and far overstayed its welcome in the park, becoming a highly invasive weed in the area. This plant is known as Lapsana communis or nipplewort. It is an annual dicot that is native to Europe and Asia, but is considered invasive in Canada and the United States. In the U.S., the weed is most common west of the Cascades in the Pacific Northwest. It is in the Asteraceae family (aka the aster, daisy, or sunflower family), and like dandelions or common groundsel, nipplewort is part of the weedy side of the family.

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The name itself has an interesting history that originated around 350 years ago when an Englishman by the name of John Parkinson named the plant after he heard that it was useful for topical treatment of ulcers for women on certain areas of their bodies. It was also an herbal treatment for nursing mothers, and was used to aid cows and goats that were having trouble being milked. Another source of the name is said to have come from the shape of the basal lobes and their resembling features. Because nipplewort is edible, its leaves can be cooked like spinach or served raw in only the most hipster of salads.

In terms of its anatomy, nipplewort is about one to three and a half inches in height, has alternate, ovular, lobed, rich green leaves, and composite yellow flowers with about 13 petals – similar in resemblance to a dandelion. They flower from June to September and are pollinated by various insects. Seed set occurs in July to October. The plant then spreads through reseeding, and one plant can produce 400 to 1,000 seeds that put out shoots in fall and spring.

Consult a fellow botanist to find out more about Lapsana communis, especially if you are curious to know if it has invaded your territory. If it has, consider entertaining dinner guests with this unusual plant.

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