3. Clematis fremontii S. Watson (Fremont’s leather flower)

C. fremontii var. riehlii R.O. Erickson

Pl. 513 g, h; Map 2351

Plants with perfect flowers, with elongate rhizomes, the stems herbaceous, erect or nearly so, not twining or climbing, 0.2–0.5(–0.7) m long. Leaves all simple, leathery in texture, the minor veins forming a raised network, the margins entire, the upper surface green, the undersurface pubescent with long white hairs along the main veins, paler but not glaucous. Flowers solitary. Perianth urn-shaped, the sepals 18–32 mm long, erect to somewhat incurved, reflexed toward the tip, white to greenish, purplish or pink, thickened and leathery, with membranous, crisped margins 0.5–2.0 mm wide, the outer surface hairy, the inner surface glabrous. Fruits with the beak 1.5–3.5 cm long, glabrous. 2n=16. April–May.

Uncommon in the eastern portion of the Ozark Border Division and disjunctly in Ozark County (Kansas, Nebraska, Missouri, and Georgia). Dolomite glades and occasionally tops of bluffs; also occasionally roadsides.

In glades where it occurs, Fremont’s leatherflower is often a conspicuous element. It is the only nontwining, herbaceous species of Clematis in the state. The stems persist through the winter, sometimes breaking off toward the base, and the leaves become “skeletonized,” turning brown and papery, with the tissue drying and breaking away, leaving the lacelike network of veins intact. Ralph Erickson (unpublished observations), who studied Missouri populations over about a 50-year period, found that plants of this species are very slow-growing but long-lived perennials. Plants normally require 4 or more years to reach flowering size, and individuals transplanted by him as young plants in about 1940 along a transect up a gladey slope in southern Franklin County were nearly all still growing in place when revisited in 1988, but had not spread significantly.

Missouri populations of C. fremontii have sometimes been treated as var. riehlii (Steyermark, 1963), based upon supposed differences in stem height and leaf shape. Keener (1967) noted that these characters are too variable across the species’ distribution to permit recognition of infraspecific taxa.