20. Clematis texensis Buckley, Proc. Acad. Nat. Sci. Philadelphia. 13: 448. 1862.
Scarlet clematis, crimson clematis
Viorna coccinea (A. Gray) Small
Stems viny, to 3 m, glabrous or sometimes ± hirsute near nodes. Leaf blade 1-pinnate; leaflets 6-10 plus additional tendril-like terminal leaflet, ovate to nearly round, unlobed, 2-3-lobed, or most proximal occasionally 3-foliolate, 1-9 × 1-6 cm, leathery, ± prominently reticulate adaxially; surfaces abaxially usually glabrous, occasionally sparsely pubescent, glaucous. Inflorescences axillary, 1-7-flowered. Flowers ovoid to urn-shaped; sepals rose-red to scarlet abaxially and at tip adaxially, ovate-lanceolate, 1.5-3 cm, margins not expanded, thick, not crispate, tomentose, tips acute to acuminate, recurved, abaxially glabrous. Achenes: bodies appressed-pubescent; beak 4-7 cm, plumose. 2 n = 16.
Flowering spring-summer (Mar-Jun). Woodlands, calcareous cliffs, and stream banks; 80-700 m; Tex.
Although widely cultivated because it is the only species of Clematis with truly red flowers, C . texensis is native only to the southeastern part of the Edwards Plateau, Texas.