Fl. N. Amer. 1: 8. 1838.
Stems erect, 2-6 dm, nearly glabrous to moderately pilose. Leaves usually simple. Leaf-blade unlobed or 2-3-lobed, occasionally divided into 3-5 leaflets; leaflet blades or lobes linear to narrowly elliptic-lanceolate, or unlobed leaf-blades elliptic to ovate, 1.5-10 × 0.2-2.5 (-3.5) cm, thin, not prominently reticulate; surfaces glabrous, not glaucous. Inflorescences terminal, flowers solitary; bracts absent or sometimes distal pair of leaves smaller, bractlike. Flowers narrowly bell-shaped; sepals uniformly violet-blue, oblong-lanceolate, 2-5.5 cm, margins narrowly expanded distally to ca. 1 mm wide, thin, crispate, proximally tomentose, glabrous where expanded, distally ± tomentose, tips acuminate, spreading to recurved, abaxially glabrous. Achenes: bodies long-pubescent; beak 6-10 cm, plumose. 2n = 16.
Phenology: Flowering all year.
Habitat: Sandy, flat pine woods
Elevation: 0-50 m
The long peduncles (10-30 cm) elevating the flowers well above the leaves are unique to Clematis baldwinii among the simple-leaved species of Clematis subg. Viorna in the flora. Broad-leaved, large-flowered plants have been segregated as C. baldwinii var. latiuscula, but many intermediates connect the extremes, and flower size is not well correlated with leaf shape. As noted by C. S. Keener (1975), leaf shape appears to be uncorrelated with distribution; collections from a single population often include broad- and narrow-leaved plants.
No values specified."thick" is not a number."dm" is not declared as a valid unit of measurement for this property.