Summer of Weeds: Flower of an Hour

Hibiscus trionum is a great example of an ornamental plant becoming a widespread weed. Its common name, flower of an hour, refers to its short-lived blooms. Other common names include Venice mallow, bladder hibiscus, bladderweed, modesty, and shoofly. Native to southern Europe and tropical to subtropical parts of Asia and Africa, it was introduced to America as an attractive addition to annual flower beds. It is now naturalized in many states across the country.

Hibiscus is a huge genus in the family Malvaceae, consisting of species found throughout warmer parts of the world. H. trionum is a warm season annual that grows to around two feet tall and has the habit of a sprawling, decumbent vine; an upright, many-branched mound; or something in-between. Its leaves are alternately arranged and three-lobed with coarsely toothed margins. The flowers are solitary and borne in the axils of leaves. They are creamy white to pale yellow with a purple-brown center, and are both cross- and self-pollinated.

flower of an hour (Hibiscus trionum)

Flowering occurs on sunny days throughout the summer. The ephemeral flowers promptly produce a balloon-shaped seed capsule that is hairy and papery with prominent purple veins. Once mature, the capsules split open at the top to reveal five compartments lined with brown to black, kidney- or heart-shaped seeds. Every part of this plant is attractive and interesting to look at, which is why it is no surprise that it is welcome in many flower beds.

Seed capsule of flower of an hour (Hibiscus trionum)

Sites that are in full sun with fertile soil and regular moisture are sought after by flower of an hour. Less fertile soils are still prone to invasion. As with many weeds, disturbance is key, so it is often found in agricultural fields, rangelands, along roadsides, and in vacant lots and construction sites. Its presence in natural areas is a result of escaping from garden beds, agricultural fields, etc.

When we choose to grow plants that have a history of escaping into natural areas, we should be aware of both our proximity to natural areas and the dispersal mechanisms of the plants. Exotic plants that reproduce reliably and prolifically by seed, such as flower of an hour, should be considered unsuitable for gardens that are adjacent to natural areas.

This is because many popular ornamental plants have become invasive in the wild. Plants that are perfectly welcome in our gardens manage to find suitable habitat in natural areas, potentially threatening the livelihood of native plants and/or altering ecological processes such as fire regimes. An example of this where I live is bachelor’s buttons (Centaurea cyanus), which has escaped from gardens and invaded the Boise Foothills. While the impact of this invasion is not well-studied, the speed at which this plant has spread is disconcerting. Even more disconcerting is the fact that seeds of this and other European and Asian species are commonly found in “wildflower” seed mixes distributed throughout North America.

While I am sympathetic towards weeds, I also see them as one of the best reminders of the impacts that humans can have on the planet. They are clear indicators that every step we take has consequences. We should be mindful of this, and we should continue to have the tough conversations that issues like weeds and their impacts encourage us to have. There are no easy answers, but the dialogue must go on. Because all of us – gardeners and non-gardeners/ecologists and non-ecologists alike – generally have an opinion about weeds, they seem like a pretty good place to start.

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From the book Invasive Plant Medicine by Timothy Lee Scott

The nature of a weed is opportunistic, and we, as humans, have created enormous holes of opportunity for these plants to fill. They have adapted to be at our side, waiting for those favorable times to cover the exposed soils that we continually create. With ever-changing genetics of form, function, and transmutation, weeds have evolved to withstand the punishments that humans unleash upon them.

Summer of Weeds: Stinking Lovegrass

There are so many weedy grasses that we would be remiss if we let the Summer of Weeds go by without discussing at least one of them. As obnoxious and ecologically harmful as some of these grasses can be, they are easy to ignore, simply because they are not as showy and eye-catching as other weeds. They can also be difficult to identify, particularly when they are not flowering. To the untrained and unappreciative eye, all grasses appear alike and most are fairly uninteresting.

But some of them have great common names, like Eragrostis cilianensis, commonly known as stinking lovegrass, candygrass, or stinkgrass. This plant earns the name “stink” on account of the unpleasant odor that is released through tiny glands in its foilage and flower head. Probably due to my poor sense of smell, my nose doesn’t pick it up very well, but from what I can tell it has a funky or, as Sierra put it, “musky” smell. I imagine if you were to come across a large patch of stinking lovegrass blowing in the breeze, the smell would be detectable.

stinking lovegrass (Eragrostis cilianensis)

Eragrostis cilianensis is a short (up to two feet tall) annual grass from Eurasia and Africa. It is naturalized across much of North America. It has hollow and jointed stems with flat or folded leaves. Where the leaf blade wraps around the stem (an area called the ligule) there is a tuft of fine hairs. The inflorescence is highly branched, and the branches are lined with several compact, flat florets. The appearance of the flower head is highly variable, from tight and compact to spread out and open.

Inflorescences of stinking lovegrass (Eragrostis cilianensis)

Stinking lovegrass likes sandy or gravelly, dry soils in open, regularly disturbed areas with full sun. It is very drought tolerant and thrives in hot temperatures, which is why it is unfazed growing in the cracks of sidewalks and pavement. It can grow in rich, fertile soil as well, and so it often makes an appearance in vegetable gardens, agricultural fields, and ornamental garden beds.

Stinking lovegrass growing in a crack between the pavement and the sidewalk

There are dozens of species in the genus Eragrostis, with representatives around the world. A few are native to North America, and a few others have been introduced. Provenance aside, all have the potential to be weedy. Eragrostis curvula, weeping lovegrass, is an aggresive invader in some regions. Eragrostis minor, lesser lovegrass, is similar to stinking lovegrass, not only in appearance but also in its provenance and status as a weed in North America. In Wild Urban Plants of the Northeast, Peter Del Tredici mentions two North American natives that can be weedy along roadsides and in vacant lots, sidewalk cracks, garden beds, and elsewhere: E. pectinacea (Carolina lovegrass) and E. spectabilis (purple lovegrass). Last but not least, Eragrostris tef (aslo known as teff) is a commonly cultivated cereal crop in Ethiopia and surrounding countries, the seeds of which are harvested to make injera.

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The Idaho Weed Awareness Campaign has some fun educational materials, including a few puppets, to help teach children about noxious weeds. Mortie Milfoil is a puppet who helps spread the word about the aquatic invasive, Eurasian watermilfoil (Myriophyllum spicatum). Hannah teaches kids about poison hemlock (Conium maculatum). See Hannah’s video below:

Summer of Weeds: Lambsquarters

Since we seem to be on the topic of edible weeds we may as well discuss lambsquarters, another frequently present and commonly eaten, nutritious and versitile weed. Botanically known as Chenopodium album, it is a member of the family Amaranthaceae and therefore related to several common (and uncommon) agricultural crops, including spinach (Spinacia oleracea), beets (Beta vulgaris), Swiss chard (also Beta vulgaris), amaranth (Amaranthus spp.), and red orach (Atriplex hortensis). Chenopodium, a genus consisting of 100 plus species, is also cultivated in various parts of the world for its edible leaves, stems, and seeds. Chenopodium quinoa, commonly known as quinoa, is now a popular “grain” in North America after being grown for millenia by Andean cultures.

Chenopodium album is a summer annual that reaches up to 6 feet tall with sturdy, angular stems and triangular, diamond-shaped, or lance-shaped leaves with irregularly toothed margins. The leaves are green on top and mealy gray-white on bottom. The flowers are tiny, petal-less, and organized in tight clusters at the ends of branches. In Botany In a Day, Thomas Elpel describes the flowers as “little green ‘globs’ forming along an upright stalk, sometimes colored with specks of yellow.” They are generally wind-pollinated, but are occassionally visited by pollinating insects. Each plant can produce tens of thousands of seeds, which are potentially viable for up to 40 years.

Inflorescence of lambsquarters (Chenopodium album)

Lambsquartes is one of many common names for C. album (others include goosefoot, fat hen, baconweed, mealweed, frostblite, and wild spinach), and is a name with several proposed origins. Is it because the plant is commonly found growing in the manure-rich soils of barnyards? Or is it because the fuzzy undersides of the leaves are reminiscent of sheep’s wool? Perhaps it is because per weight, the harvested plants and a quarter of lamb contain roughly the same amount of protein? Who knows? Despite all this talk of sheep, however, large quantities of lambsquarters are reported to be poisonous to both sheep and pigs.

Though lambsquarters prefers nutrient-rich soils, it tolerates a wide variety of soil types, including dry, compacted, urban soil. It is drawn to all sorts of disturbed sites and is particularly abundant in gardens, agricultuaral fields, and roadsides. It readily hybridizes with other Chenopodium species, including the North American native C. berlandieri. In The Book of Field and Roadside, John Eastman calls it “one of the wold’s most abundant and noxious weeds,” because “it competes with some 40 crops [and] is especially invasive in tomato, potato, sugar beet, soybean, and corn fields.”

Eastman goes on to hint at lambsquarters’ potential for phytoremediation: “The plant accumulates high levels of nitrates and pesticides in addition to its oxalic acid content.” It also takes up heavy metals, including zinc, copper, and lead. This phenomenon is worth a future post, so stay tuned.

Leaf of lambsquarters (Chenopodium album)

That being said, when harvested from a non-polluted site, lambsquarters is a very nutritious spinach-like green both raw and cooked. Younger leaves and plants are preferred because older ones tend to be higher in oxalic acid. The seeds are also edible and, like quinoa, can be used in a similar manner as common grain and cereal crops. Harvester ants and various bird species also collect and consume the seeds. The roots of lambsquarters are high in saponin and can be used to make soap.

There are many reasons to be impressed with Chenopodium album, including its ability to tolerate drougt and frost, its adaptability to all types of soil, its highly nutritious plant parts (but also potentially toxic due to accumalation of pollutants and oxalic acid), and its competitive and persistent nature. Ehrenfried Pfeiffer, author of Weeds and What They Tell, was in awe of this “most enduring annual weed” and its goosefoot family relatives, writing: “We have the feeling that the goosefoot was destined to play a better role than to become an obnoxious weed. They follow closely man’s steps, showing their inclination to be domesticated. Probably future plant breeders may develop new cultivated varieties out of this family long after our present cultivated plants have degenerated, for it is their extreme vitality and preserverence to grow that makes the goosefoot family so interesting.”

Pfeiffer’s predictions haven’t quite come to pass, but time will tell.

More lambsquarters flowers

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According to an article posted on LiveScience, lambsquarters is one of “The Five Healthiest Backyard Weeds.” The list includes two other weeds we have covered during the Summer of Weeds: Purslane and Plantain.

Summer of Weeds: Plantains

This is a revised version of two ethnobotany posts that appeared previously on Awkward Botany: White Man’s Foot, part one and part two. Plantains have a long history of ethnobotonical uses, as well as a bad reputation of being pesky, hard-to-eliminate weeds. The two most common introduced plantain species in North America are broadleaf plantain (Plantago major) and lanceleaf plantain (Plantago lanceolata). Wherever our daily travels take us, chances are there is a plantain growing nearby.

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Plantago major is in the plantain family (Plantaginaceae) a family that consists of at least 90 genera, including common ornamental plants like Veronica (speedwells), Digitalis (foxgloves), and Antirrhinum (snapdragons). The genus Plantago, commonly known as plantains, consists of around 200 species distributed throughout the world in diverse habitats. Most of them are herbaceous perennials with similar growth habits.

Originating in Eurasia, P. major now has a cosmopolitan distribution. It has joined humans as they have traveled and migrated from continent to continent and is now considered naturalized throughout most temperate and some tropical regions. P. major has a plethora of common names – common plantain being the one that the USDA prefers. Other names include broadleaf plantain, greater plantain, thickleaf plantain, ribgrass, ribwort, ripplegrass, and waybread. Depending on the source, there are various versions of the name white man’s foot. Along the same line, a common name for P. major in South Africa is cart-track plant.

common plantain (Plantago major)

Common plantain starts by forming a rosette of broad leaves usually oriented flat against the ground. The leaves are egg-shaped with parallel veins; occasionally, leaf margins are faintly toothed. The inflorescence is a leafless spike up to 20 centimeters tall or taller with several tiny flowers that are a dull yellow-green-brown color. The flowers are wind pollinated and highly prone to self-pollination. The fruits are capsules that can contain as many as 30 seeds; an entire plant can produce as many as 15,000 seeds. The seeds are small, brown, sticky, and easily transported by wind or by adhering to shoes, clothing, animals, and machinery. They require light to germinate and can remain viable for up to 60 years.

Common plantain prefers sunny sites but can also thrive in part shade. It adapts to a variety of soil types but performs best in moist, clay-loam soils. It is often found in compacted soils and is very tolerant of trampling. This trait, along with its low-growing leaves that easily evade mower blades, explains why it is so common in turf grass. It is highly adaptable to a variety of habitats and is particularly common on recently disturbed sites (both natural and human caused). It is an abundant urban and agricultural weed.

Illustration of three Plantago species from Selected Weeds of the United States (Agriculture Handbook No. 366) circa 1970

Even though it is wind pollinated, its flowers are visited by syrphid flies and various bee species which feed on its pollen. Several other insects feed on its foliage, along with a number of mammalian herbivores. Cardinals and other bird species feed on its seeds.

Humans also eat plantain leaves, which contain vitamins A, C, and K. Young, tender leaves can be eaten raw, while older leaves need to be cooked as they become tough and stringy with age. The medicinal properties of  P. major have been known and appreciated at least as far back as the Anglo-Saxons, who likely used a poultice made from the leaves externally to treat wounds, burns, sores, bites, stings, and other irritations. It has also been used to stop cuts from bleeding and to treat rattlesnake bites. Apart from external uses, the plant was used internally as a pain killer and to treat ulcers, diarrhea, and other gastrointestinal issues.

P. major has been shown to have antibacterial, anti-inflammatory, antioxidant, and other biological properties; several chemical compounds have been isolated from the plant and deemed responsible for these properties. It is for this reason that P. major and other Plantago species have been used to treat such a diverse number of ailments. The claims are extensive and worth exploring. You can start by visiting the following sites:

Excerpts about plantains 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.”

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

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.”

An excerpt from Weeds: In Defense of Nature’s Most Unloved Plants by Richard Mabey

“Plantain, ‘the mother of 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.)”

Summer of Weeds: Common Mullein

The fuzzy, gray-green leaves of common mullein are familiar and friendly enough that it can be hard to think of this plant as a weed. Verbascum thapsus is a member of the figwort family and is known by dozens of common names, including great mullein, Aaron’s rod, candlewick, velvet dock, blanket leaf, feltwort, and flannel plant. Its woolly leaves are warm and inviting and have a history of being used as added padding and insulation, tucked inside of clothing and shoes. In Wild Edible and Useful Plants of Idaho, Ray Vizgirdas writes, “the dried stalks are ideal for use as hand-drills to start fires; the flowers and leaves produce yellow dye; as a toilet paper substitute, the large fresh leaves are choice.”

Common mullein is a biennial that was introduced to eastern North America from Eurasia in the 1700’s as a medicinal plant and fish poison. By the late 1800’s it had reached the other side of the continent. In its first year it forms a rosette of woolly, oblong and/or lance-shaped leaves. After overwintering it produces a single flower stalk up to 6 feet tall. The woolly leaves continue along the flower stalk, gradually getting smaller in size until they reach the inflorescence, which is a long, dense, cylindrical spike. Sometimes the stalk branches out to form multiple inflorescences.

First year seedlings of common mullein (Verbascum thapsus)

The inflorescence doesn’t flower all at once; instead, a handful of flowers open at a time starting at the bottom of the spike and moving up in an irregular pattern. The process takes several weeks to complete. The flowers are about an inch wide and sulfur yellow with five petals. They have both female and male sex parts but are protogynous, meaning the female organs mature before the male organs. This encourages cross-pollination by insects. However, if pollination isn’t successful by the end of the day, the flowers self-pollinate as the petals close. Each flower produces a capsule full of a few hundred seeds, and each plant can produce up to 180,000 seeds. The seeds can remain viable for over 100 years, sitting in the soil waiting for just the right moment to sprout.

Common mullein is a friend of bare, recently disturbed soil. It is rare to see this plant growing in thickly vegetated areas. As an early successional plant, its populations can be abundant immediately after a disturbance, but they do not persist once other plants have filled in the gaps. Instead they wait in seed form for the next disturbance that will give them the opportunity to rise again. They can be a pest in gardens and farm fields due to regular soil disturbance, and are often abundant in pastures and rangelands because livestock avoid eating their hairy leaves. Because of its ephemeral nature, it is generally not considered a major weed; however, it is on Colorado’s noxious weed list.

Several features make common mullein a great example of a drought-adapted plant. Its fleshy, branching taproot can reach deep into the soil to find moisture, the thick hairs on the leaves help reduce water loss via transpiration, and the way the leaves are arranged and angled on the stalk can help direct rain water down toward the roots.

Common mullein has an extensive history of ethnobotanical uses. Medicinally it has been used internally to treat coughs, colds, asthma, bronchitis, and kidney infections; and as a poultice to treat warts, slivers, and swelling. The dried flower stalks have been used to make torches, and the fuzzy leaves have been used as tinder for fire-making and wicks in lamps.

The hairy leafscape of common mullein (Verbascum thapsus)

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From Gaia’s Garden by Toby Hemenway

Here’s why opportunistic plants are so successful. When we clear land or carve a forest into fragments, we’re creating lots of open niches. All that sunny space and bare soil is just crying out to be colongized by light- and fertlity-absorbing green matter. Nature will quickly conjure up as much biomass as possible to capture the bounty, by seeding low-growing ‘weeds’ into a clearing or, better yet, sprouting a tall thicket stretching into all three dimensions to more effectively absorb light and develop deep roots. … When humans make a clearing, nature leaps in, working furiously to rebuild an intact humus and fungal layer, harvest energy, and reconstruct all the cycles and connections that have been severed. A thicket of fast-growing pioneer plants, packing a lot of biomass into a small space, is a very effective way to do this. … And [nature] doesn’t care if a nitrogen fixer or a soil-stabilizing plant arrived via continental drift or a bulldozer’s treads, as long as it can quickly stitch a functioning ecosystem together.

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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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.”

Summer of Weeds: Henbit and Purple Deadnettle

There are weeds for every season. Now that we are heading into the hot days of summer, spring weeds (if they haven’t already) are fading. There is a parallel between them and the spring wildflowers we love. They start early, greening up and flowering even before there are leaves on the trees. They exploit the sun made available before deciduous trees and shrubs can hog it all, and they take advantage of the moisture in the soil brought by winter snowfall and spring rain. They thrive in cool temperatures, and their flowers provide early pollen and nectar for emerging pollinators. One major difference between spring ephemeral weeds and spring ephemeral wildflowers is that, despite having similar strategies and providing similar services, the spring weeds aren’t from here; and so we look down on them.

Two common, annual, spring weeds that are easily recognizable – but often mistaken for one another – are henbit and purple deadnettle. Both are in the genus Lamium and the family Lamiaceae (the mint family) and both arrived from Europe. Looking closely at the leaves is the best way to tell these two apart. The upper leaves of henbit (Lamium amplexicaule) lack petioles and are round or oval with rounded teeth. The upper leaves of purple deadnettle (Lamium purpureum) are crowded around the stem, have short petioles, sharper teeth, and are more spade-shaped, coming to a point at the tip. The uppermost leaves of purple deadnettle are a distinct reddish-purple. Identify That Plant offers a great tutorial to help tell these and groundy ivy (another spring-occurring, annual weed in the mint family) apart.

henbit (Lamium amplexicaule)

Henbit prefers full sun and moist, rich soils. It can have either a prostrate or an erect growth habit. In urban environments it is commonly found in lawns, garden beds, and drainage ditches. It is common in agricultural crops and fallow fields as well. According to Weeds of North America, “henbit is poisonous to livestock, especially sheep, causing the animal to stagger;” it is also a host for aster yellows, tobacco etch, and tobacco mosaic viruses. Purple deadnettle inhabits similar sites, often forming a dense groundcover. While henbit and purple deadnettle are highly attractive to bees, they do not always require insect pollination and can self-pollinate instead. Each plant can produce dozens of seeds, and seeds remain viable in the soil for as long as 25 years.

Plants in the genus Lamium are commonly referred to as dead-nettles because they resemble stinging nettle (Urtica dioica) and other plants in the genus Urtica. Lamiums do not posses the stinging quality, and so they are “dead.”  The young leaves, shoots, and flowers of henbit and purple deadnettle are edible and can be eaten raw or cooked. Check out Eat the Weeds for more details.

Illustration of henbit (Lamium amplexicaule) from Selected Weeds of the United States (Agriculture Handbook No. 366) circa 1970

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purple deadnettle (Lamium purpureum)

Quote of the Week:

From Wild Urban Plants of the Northeast by Peter Del Tredici

From a utilitarian perspective, a weed is any plant that grows by itself in a place where people do not want it to grow. The term is a value judgment that humans apply to plants we do not like, not a biological characteristic. Calling a plant a weed gives us license to eradicate it. In a similar vein, calling a plant invasive allows us to blame it for ruining the environment when really it is humans who are actually to blame. From the biological perspective, weeds are plants that are adapted to disturbance in all its myriad forms, from bulldozers to acid rain. Their pervasiveness in the urban environment is simply a reflection of the continual disruption that characterizes this habitat. Weeds are the symptoms of environmental degradation, not its cause, and as such they are poised to become increasingly abundant within our lifetimes.

A patch of dead-nettle (Lamium sp.) – photo credit: Amy Trampush (Thank you, Amy!)