Narrow-leaved purple coneflower, blacksamson echinacea

Echinacea angustifolia var. strigosa McGregor

Plants to 70 cm (roots usually fusiform, ± branched). Herbage moderately to densely hairy (induments relatively harsh, hairs spreading, ca. 1–2 mm). Stems mostly green to purplish. Basal leaves: petioles 2–12 cm; blades (1-), 3-, or (5-)nerved, elliptic to lanceolate, 7–30 × 0.5–2.5(–4) cm, bases cuneate to attenuate, margins entire (usually ciliate). Peduncles 10–30 cm. Phyllaries lanceolate to ovate, 6–12 × 1–2.5 mm. Receptacles: paleae 9–14 mm, tips purple, straight, sharp-pointed. Ray corollas pink to purplish, laminae reflexed, 15–40 × 5–8 mm, sparsely hairy abaxially. Discs conic to hemispheric, 15–30 × 20–35 mm. Disc corollas 5–7+ mm, lobes usually purple. Cypselae often bicolored, tan proximally, dark brown banded distally, 4–5 mm, faces ± smooth, usually glabrous; pappi to ca. 1 mm (major teeth 0–4). 2n = 22, 44.

Flowering late spring–mid summer, dry prairies, barrens, rocky to sandy-clay soils; 100–1600 m; Man., Sask.; Colo., Iowa, Kans., Minn., Mo., Mont., Nebr., N.Mex., N.Dak., Okla., S.Dak., Tex., Wyo.

R. L. McGregor (1967, 1968) recognized Echinacea angustifolia var. strigosa as a complex of diploid and tetraploid populations ranging geographically from southeastern Kansas and central Oklahoma to north-central Texas. He noted that var. strigosa is distinguishable by its shorter stature, stems frequently branched, somewhat flexuous, distally strigose to strigose-hirsute that retain, in part, a green color upon drying. A hybrid origin for var. strigosa was suggested based on the morphologic intermediacy of natural populations compared to synthesized hybrids between typical E. angustifolia and E. atrorubens (McGregor 1968). Populations along the southern boundary of the range of var. strigosa are tetraploid. In their morphometric analyses, S. E. Binns et al. (2002) did not recognize var. strigosa; they found it indistinguishable from typical E. angustifolia.