Have you seen inconspicuous, tiny, white, flower-clusters rising mysteriously over the brown of winter lawn and garden? These are likely specimens of Hairy Bittercress (Cardamine hirsuta) . This minute, common plant is the earliest to bloom in our area of northeastern, USA. While other wild plants are simply struggling to open their swelling buds and produce a few tiny green leaves, Hairy Bittercress has already produced flowers and set seeds. During this year’s mild winter I have observed it blooming in my lawn and still-barren garden and growing luxuriantly in the wide cracks of a concrete walk as early as late February .
The minute white flowers on thin long stems are only @ 1/8 inch or a few millimeters across, and occur in a whorl. The flowers vibrate on their long stems in every zephyr of the cool late-winter air. This movement may aid in self-pollination, the means by which this plant pollinates and forms seeds. You will need a hand lens to see the flowers clearly. But if you do, you may easily identify the family to which the plant belongs as the “crucifera” (meaning “cross bearer”) since the tiny petals (when opened) form a distinct Christian cross pattern.
The cruciferae (or mustard family, now also called Brassicacea) are a large group of wild, and domesticated plants and vegetables such as wild mustard, winter cress, cabbage, broccoli, Brussels sprouts, cauliflower, collards, turnips, and kale.
The ground hugging leaves of Hairy Bittercress (called the “basal rosette”) is formed by an emergent ring of pinnately compound leaves, composed of seven or more rounded leaflets, each often ending in a sharp terminal point. Thin stems arise from the rosette and branch. Some of these stems carry flowers and may also bear leaves which form on the stem above the rosette. These “stem leaves” are also pinnately compound, but with five to seven elongate leaflets. Pollinated flowers form unusually long, thin, seed pods called siliques. Later in the season, when most flowers have formed their long, dark-blue or violet colored siliques, the plant takes on a “hairy” appearance which may be the origin of the “hirsuta” (hairy) species name. When mature, these seed pods split open violently in a coiling action that launches the seeds and spreads them widely, (a property known as “ballistic seed dispersal”). This adaptation likely reduces competition with the parent plant. It is reported that this action may also tend to repel small herbivores and thus protect the plant from herbivory.
Research on this inconspicuous plant, often of only two centimeters (2 cm) tall, indicates it can disperse its seeds by “ballistic seed dispersal” as much as two meters (2 m)or @ 6.6 feet from the parent plant. To put that feat into perspective, compare it to a six foot tall football quarterback who with a similar ability would be able to throw a football 600 feet, 200 yards, or two football fields ( i.e. 2 cm/2m as 1/100 as 6ft/600ft). (Note: World champion quarterback, Patrick Mahomes of the Kansas City Chiefs claims (brags?) he is able to throw a football about 75-83 yards.) This very effective method of spreading seeds, as well as its early emergence in late winter, when moisture is abundant, and competition limited may in part explain why this minor plant is so common.
Like others in the crucifera group Hairy Bittercress is also good to eat. The leaves, flowers and even the long, thin seed pods are edible. The plant is not bitter, as the name seems to suggest, but is pleasantly tangy. Herbalists, wild plant foragers, and others often include this species on lists to collect as an addition to a salad, or to be added to a sandwich in place of watercress, arugula or radicchio. (Though in most circumstances, where found along modern walkways or maintained lawns, collecting this plant for consumption from these locales is not advisable. )
Like the other crucifera, Hairy Bittercress has health benefits. It is a good source of vitamin C, beta carotene and also has a compound known as glucosinolate, a supposed cancer fighting component, as do all the vegetable crucifera. Though this species is so small that enormous quantities would have to be consumed for any practical health benefit.
Glucosinolates are plant-produced chemicals found inside plant cells. When the cells are damaged, the cell can use the glycosinolates to synthesize isothiocyanates which are toxic to most animals. This tends to protect crucifera from herbivory. Ironically, these same substances when consumed by humans may help regulate inflammation, act as antioxidants, and have beneficial antimicrobial properties. Some claim anti-cancer effects as well. But like many other plant metabolites excessive consumption of these “cyanates” may have deleterious effects.
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