Meet the nice native spiderwort and the beneficial bumblebee that pollinates it.
Information on these species comes courtesy of Helen Hamilton, author of "Wildflowers and Grasses of Virginia's Coastal Plain."
The first gardener to grow native spiderwort, Tradescantia virginiana, in cultivation was John Tradescant, gardener to Charles the First of England and a subscriber to the Virginia Company, which is the origin of the plant's name, according to Hamilton. John's son traveled to Virginia in the 1630s, and sent spiderwort back to England where it became part of English cottage gardens.
"Spiderwort can be a good indicator of environmental problems since a high sensitivity to pollution and radiation causes it to mutate quickly," says Hamilton, a retired biology teacher.
"The hairs on the stamens have long been used in botany classes, because the flow of protoplasm can be viewed through a microscope. These hairs give the plant the common name "wort," being the old England word for plant. Also, the sap from the broken stem forms filaments like a spider's web or the angular leaf arrangement suggest a squatting spider.
Spiderworts are often found in abandoned gardens - along with classics like lilacs and shrub roses. Each flower lasts a day, but new blossoms continually appear. Old blooms do not fall to the ground - they seem to melt off the plant, due to enzyme activity, says Hamilton. The three petals are typically shades of purple and blue, but rose, pink, and white cultivars are offered by today's nursery trade. Propagation is by division or seed; flowering happens April-July.
The easy-grow plants tolerate full sun and adapt to part sun, and thrive in dry to moist soil. They look good as border plants, and stand out when planted against backdrops like a wall. In the wild, spiderwort inhabits dry upland forests, rocky open woods and wood edges, so providing the plant with a similar habitat makes it happy in the home garden, according to Hamilton. The plant can become aggressive, but thinning and pulling unwanted seedlings keeps it under control.
Unless acquired from a wildflower nursery, the plants sold today are usually a series of hybrids, which are sold at garden centers. Today there are more than 30 cultivars: Snow Cap has pure white flowers; Valor bears deep reddish purple flowers, both on 20-inch stems. Pauline is pink-flowered on 12-inch stems, and Concord Grape grows 18 inches high with dark bluish-green leaves contrasting with beautiful purple flowers, says Hamilson.
Eastern spiderwort ranges from New England to Georgia, Minnesota and Missouri; a western spiderwort ranges from southern Canada to Texas and Arizona.
Species of Tradescantia appear on lists of both edible and poisonous plants; minor skin irritations have resulted in some people from contact with the plant.
Bumblebees are the principal pollinators for many species of spiderwort.
More than 20,000 species of bees have been described worldwide, including 250 species of bumblebees in temperate regions of the Americas, Europe and Asia, according to Hamilton. About 46 species of bumblebees are native to North America, 21 in the eastern United States.
The common Eastern bumblebee (Bombus impatiens) frequents the Atlantic Coast, foraging farms, suburbs and urban areas. The species name refers to its favorite plant for nectar and pollen, Jewelweed (Impatiens capensis). Brown-belted bumblebee (B. grisecollis) is also common, particularly in urban areas. Two-spotted bumblebee (B. bimaculatus) has a long tongue that gathers nectar from mints; coloration is very similar to the brown-belted, Hamilton noted.
Three other species were once common along the East Coast, and are now uncommon or rarely seen. These are the American bumblebee (B. pensylvanicus), yellow bumblebee (B. fervidus) and black and gold bumblebee (B. auricomus). If you like "citizen science," the Xerces Society invites home gardeners to collect information about bumblebee sightings. The website - http://www.bumblebeewatch.org - allows you to upload personal photographs, provides information about identifying species, and sends an e-newsletter after signing in.
"Only two groups of bees are social - honeybees and bumblebees," says Hamilton.
"Honeybees have a sophisticated social structure with a queen bee producing thousands of worker bees through the season, and large amounts of honey. They nest above ground in hives. In contrast, bumblebees nest in the ground, their societies are relatively primitive, contact only a few hundred workers, do not communicate information about food location to members of the hive, and produce little or no honey."
Bumblebees are easily recognized by their large furry bodies and smooth hind legs with stiff bristles for carrying pollen. Bumblebees are among the first bees active in spring and the last bees active in the fall. They can regulate their body temperature by shivering or basking in the sun, allowing them to forage during wetter and cooler conditions than those tolerated by honeybees and other native bees. Therefore, they are important pollinators of early-blooming wildflowers and fruit crops, and need habitat with lots of blooming flowers throughout the growing season.
Learn more about bumblebees at www.bumblebeeconservation.org .
(Kathy Van Mullekom is the garden/home columnist for the Daily Press in Newport News, Va. Follow her on Facebook@Kathy Hogan Van Mullekom, on Twitter @diggindirt and at Pinterest@digginin. Her blog is at Diggin@RoomandYard.com. Email her at firstname.lastname@example.org .)