Soft-wooded plants, climbing by bending or clasping of the petioles. Stem 5- to 18-angled; pith angled or star-shaped, white, continuous, with firmer diaphragms at the nodes. Buds small, ovoid, or flattened, somewhat hairy, sessile, solitary, with 1-3 pairs of scales. Leaves opposite, withering but not falling, gradually torn off more or less piecemeal by winter winds.
Fig. 94. Clematis virginiana.
Fig. 95. Clematis viorna.
Fig. 96. Clematis verticiIlaris.
Stems glaucous and glabrous
Stems not glaucous, sometimes pubescent
b. Stems brown, finely pubescent; leaflets toothed
b. Stems red-brown, pubescent at the nodes; leaflets entire
1. C. virginiana L. Virgin's Bower. A climbing vine, more or less woody; stem finely pubescent, brown, with about 6 distinct ridges, leaves normally 3-foliate, the leaflets ovate, toothed. Thickets, Quebec to Manitoba, south to Georgia, Louisiana, and Kansas (Fig. 94).
2. C. viorna L. Leatherflower. A vine climbing to a height of 3 m. or more; stem finely pubescent, red-brown; leaves mostly pinnate, firm, entire. Rich soil of thickets, Georgia to Texas, north to Pennsylvania and Iowa (Fig. 95).
3. C. verticillaris DC. Purple Virgin's Bower. A woody-stemmed climber, glaucous and glabrous; stem 6-sided, brown; leaves trifoliate. Rock slopes, Quebec to Wisconsin, south to West Virginia and Iowa (Fig. 96).