Stems erect, not viny, 2-4(-6) dm, pubescent or pilose to ± tomentose or hirsute. Leaves simple. Leaf blade elliptic-lanceolate to ovate, unlobed, 3.5-8(-10) × 1.5-5(-6.5) cm, thin, not conspicuously reticulate; surfaces abaxially glabrous to sparsely (rarely more densely) villous on veins, not glaucous. Inflorescences terminal, flowers solitary; bracts absent. Flowers narrowly urn-shaped; sepals purplish, yellowish toward tips, oblong-lanceolate, (1.1-)1.4-3 cm, margins not expanded or less than 1 mm wide, thin, not crispate, tomentose, tips obtuse, spreading to recurved, abaxially silky- to woolly-pubescent. Achenes: bodies pilose; beak white to pale yellow, (1.5-)2-4(-4.5) cm, plumose. 2 n = 16. Flowering spring-early summer. Shale barrens; 300-800 m; Va., W.Va. Clematis albicoma is known only from shale barrens predominantly developed from the Upper Devonian Brallier Formation in nine counties of western Virginia and adjacent West Virginia.
Stem erect, 2-5 dm, simple to more often much branched, the branches usually overtopping the central axis; lvs subsessile, dark green, lance-ovate or ovate, glabrous or slightly hairy along the veins beneath when young, the larger ones mostly 4-8 נ1.5-5 cm; mature peduncles 2-10 cm; cal urceolate; sep 1.5-3 cm, densely hairy outside; achenes densely hairy, the hairs of the distal portion and the base of the style reflexed or widely divergent; mature style mostly 2-4 cm, densely plumose; 2n=16. Apr.-June. Local on shale barrens in w. Va. and e. W.Va.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.