Robin’s-plantain (Erigeron pulchellus var. pulchellus) of the Aster (Asteraceae) family has been documented in the U.S. from eastern Texas to southeastern Kansas to Minnesota thence east and south to the nation’s borders (although it is rare in Florida and restricted to the panhandle).* In Arkansas, it has been documented throughout much of the state except for portions of the Mississippi Alluvial Plain and the West Gulf Coastal Plain. This stoloniferous wildflower is found in rich, well-drained, rocky to sandy soils in partial shade, such sites being in open woods, savannahs and thickets or on stream banks and terraces. The genus name is from Greek words meaning “early” and “old man” which may allude to the early appearance of flowers and to white hairs on mature fruit, and the specific epithet is from Latin for “beautiful”. Other common names include blue spring daisy, poor Robin’s fleabane and hairy fleabane.
A plant (as used herein: a single cluster of basal leaves along with or without a flowering stem), with long tan fibrous roots, produces white smooth unbranched stolons. Stolons, growing at or just below soil surface from just below basal leaves, are about one-sixteenth inch in diameter and up to a foot long. Small white bracts are found at nodes along the stolon and a few long white roots grow from nodes. Ends of stolons turn upward to produce a single new plant. With multiple stolons growing from a plant, a dense colony can form. Plants and stolons are both perennial.
Robin’s-plantain is covered with dense soft hairs (pubescent). Mature plants produce two types of leaves, basal and cauline (on stem). For both basal and cauline leaves, the upper leaf blade surfaces are a uniform grayish medium green with a lighter green undersurface. The upper leaf surface has a broad main vein that is a very light green.
Basal leaves in early spring, about 1¾ inches long and ¾ inch wide, are rough and feel rather coarse. These oblanceolate to paddle-shaped leaves may have two or three broadly toothed lobes above mid-leaf that are oriented toward the rounded tip or the entire upper margin, including the tip, may be crenulated. Basal leaves remain on the plant throughout the growing season and may then be 5 inches long and 1½ inches wide. Old leaves are still present when new leaves appear the next year.
Basal leaves transition into clasping cauline leaves. These leaves, larger (about 3 inches long and ¾ inch wide) and more numerous lower on the stem, decrease in size and number toward the top, becoming very small in the inflorescence. They are densely covered with soft hairs (pubescent), especially on the upper side. The broadly lanceolate, sessile and twisted cauline leaves deteriorate with the stem after fruit has matured.
The inflorescence begins to form in late winter to early spring with the emergence of a stem at the center of mature plants. The round, hairy stems have alternating lines of brown and green. Stems are topped by several to about eight prominent flower head buds arranged in corymb fashion. The buds, largest at top of stem, are round when viewed from above and bowl-shaped when viewed from the side. Heads bloom from top of corymb to bottom while stems continue to grow, eventually reaching about 1½ feet tall.
Flower heads (capitulums), 1 to 1½ inches wide, have 50 to 80 or more fertile ray florets and many densely packed fertile disk florets. Ray florets, with white to pale violet, slender corollas called ligules, surround a flat disk of florets with yellow tubular corollas. A pappus of silky hairs (morphologically a modified calyx) occurs at the base of corollas. Florets are attached to a domed, soft receptacle subtended by an involucre of many appressed, imbricate (overlapping) lanceolate bracts called phyllaries. Following anthesis, ray and disk florets produce an elongate achene with a tuft of white hairs (the pappus). Seed dispersal is by wind.
In a garden or natural setting, Robin’s-plantain can be an attractive ground-cover year round. The plant shows best in partially shaded areas where other ground vegetation is sparse. Its early spring flowering stems with fairly large daisy-like flower heads are showy. In ideal growing conditions, due to its stoloniferous habit, a colony may need to be restrained by removing excess plants.
Four other fleabanes also occur in Arkansas: daisy fleabane (Erigeron annuus), Philadelphia fleabane (Erigeron philadelphicus var. philadelphicus), prairie fleabane (Erigeron strigosus), and slender-leaf fleabane (Erigeron tenuis). Most are annual to biennial in habit, while Philadelphia fleabane may be a short-lived perennial. None have prominent stolons, though, and flower heads are both more numerous and smaller than on Robin’s-plantain.
*Two other varieties of Erigeron pulchellus have been identified in the U.S.; namely Erigeron pulchellus var. brauniae (KY, OH, MD and WV) and Erigeron pulchellus var. tolsteadii (MN). Neither is found in Arkansas.
Article and photographs by ANPS member Sid Vogelpohl