This week for Flora and Fauna Friday it’s a tall frost-fractured fall flower found along forest fringes, Frostweed (Verbesina virginica).
Frostweed is a common fall wildflower here on Edisto Island. Its towering eye-high stems line many a semi-shaded road shoulder from September through October. Frostweed prefers damp soil and partial sun, so its natural habitat is forest edges and its less-natural habitats are road shoulders, field edges, and gardens. Frostweed is a perennial that spreads via its roots. In the right conditions, it has vigorous growth and a vigorous rate of spread. This makes it a great addition to most native plant gardens as what I call an “anchor plant”, one you can always depend on if nothing else blooms and one that you can’t uproot (or kill with neglect) once it digs itself in.
Speaking of blooms, that’s why we’re speaking about Frostweed. Frostweed is a fantastic nectar and pollen plant for bees, flies, butterflies, wasps, and more! It’s a member of the Aster family and the Crownbeard genus. Our three common Crownbeard species all look much the same: tall stems, large leaves dangling from that stem, and a small dome of flowers with an unkempt look. Our other species of Crownbeard are predominantly found in the upstate and both are yellow-flowered. However, Frostweed has snow-white flowers. As I alluded, the flowers of Frostweed and other Crownbeards are disheveled looking. Each individual flower head looks like a typical compound Aster flower, except that they all appear to be missing petals. Each flower-head is a little different, some have two petals, others five, and most have three or four. It’s very unorganized looking up close but not so noticeable from a few yards back. Regardless of their naturally gap-toothed appearance, the flowers are adored by pollinators and, when dead and dried, the stems of Frostweed provide nesting cavities for mason wasps, native bees, and ants and their thick growth creates cover for birds and small mammals.
Yet, the snow-white flowers of Frostweed are not how it got its icy alias. That common name originated from a serenely beautiful quirk of its stems, a phenomena we rarely get to see on Edisto Island. At the first hard frost of the year, the stems of Frostweed will split at the base. Through the thin slits split into the stem will grow gossamer ribbons of ice. As the moisture in the stem freezes and expands, it pushes outward. As the stem dries it pulls water from elsewhere in the stem and will continue to growth the ribbon of ice for several inches or more until it exhausts its water. The ice ribbons have a silky smooth, finely striped appearance, like shining white locks of hair. They last but a morning and melt away as the sun rises. A common sight in late fall in much of the upper south but an infrequent and short-lived sight here on Edisto Island.
