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1 Flowers numerous, in compound cymose- paniculate inflorescences; sepals white; filaments glabrous; [subgenus Clematis]. |
2 Flowers perfect, with 5-10 carpels; anthers 1.5-3 mm long; leaf margins entire (rarely cleft or with 1-2 rounded teeth or small lobes); leaflets (3-) 5 (-7), often variegated with a silver blaze along the midvein; [ exotic, in disturbed areas] |
2 Flowers mostly polygamo- dioecious, the pistillate with 18-60 carpels; anthers 0.5-1 mm long; leaf margins coarsely toothed with acute teeth; leaflets 3 ( C. virginiana) or 5-7 ( C. catesbyana), uniformly green; [native, though sometimes weedy]. |
3 Leaflets with terminal lobe (past last teeth) >2× as long as wide; plumose achene beak 4-9 cm long |
3 Leaflets with terminal lobe (past last teeth) <2× as long as wide; plumose achene beak 2.5-5 cm long |
4 Leaves (3-) 5-7-foliolate; pistillate flowers with 18-35 carpels |
4 Leaves 3-foliolate; pistillate flowers with 40-60 carpels |
1 Flowers solitary or in groups of 3's; sepals usually at least partly bluish, purplish or red; filaments pubescent. |
5 Leaves (most or all of them) simple, sessile or subsessile; plant an erect herb to 7 dm tall; [subgenus Viorna]. |
6 Leaves glaucous and glabrous beneath, the uppermost commonly pinnate and tendril-bearing |
6 Leaves green and usually pubescent beneath ( glabrous in C. baldwinii), the uppermost usually simple and entire, neither pinnate nor tendril-bearing (though occasionally lobed). |
7 Leaves of flowering material soft- pubescent beneath, the largest 3-9 cm wide, with stomates on the lower surface only; leaves of fruiting material usually light green with the secondary and tertiary veins forming prominent reticulations on the upper surface. |
8 Stems and leaves usually densely sericeous- woolly; sepal backs densely sericeous; mature styles white to pale yellow, sharply recurved and flexuous; [of shale barrens and calcareous woodlands of w. VA] |
8 Stems and leaves villous; sepal backs moderately sericeous- pilose; mature styles yellowish-white to deep tawny, loosely spreading- recurved; [of various woodlands, fairly widespread in our area] |
7 Leaves of flowering material glabrous to sparsely pilose beneath, the largest 2-5 cm wide (or 3.5-11 cm wide in C. fremontii), with stomates on both surfaces; leaves of fruiting material often dark green, either with the secondary and tertiary veins forming prominent reticulations on the upper surface ( C. fremontii) or the upper with the secondary and tertiary veins not forming prominent reticulations on the upper surface ( C. albicoma, C. viticaulis, and C. baldwinii). |
9 Sepal tips acuminate; achene bodies cobwebby- tomentose toward the tip ( C. fremontii) or long pilose ( C. baldwinii) |
10 Leaf blades 0.2-2.5 (-3.5) cm wide, not notably reticulate on the upper surface; beak of the achene plumose with long hairs; [of wet pinelands of n. FL southward] |
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9 Sepals tips obtuse to acute; achene bodies pilose throughout; [of shale barrens of w. VA and WV]. |
11 Sepal backs villous; pubescence on the summit of the achene and the base of the style spreading or reflexed; mature styles white to pale yellow, sharply recurved and flexuous |
11 Sepal backs finely puberulent; pubescence on the summit of the achene and the base of the style closely appressed- ascending; mature styles tawny to deep reddish-brown, loosely spreading- recurved |
5 Leaves (most of them) compound, petiolate; plant a trailing or climbing vine or shrubby, to many meters long (or erect or ascending in C. addisonii and C. socialis). |
12 Sepals thin in texture, 3-5 cm long, soft- villous, neither apically recurved nor with broad, strongly crisped margins; leaves 3-foliolate; [subgenus Atragene] |
12 Sepals thick in texture, 1-5 cm long, short- sericeous, apically recurved; leaves 1-11-foliolate; [subgenus Viorna]. |
13 Lower surface of leaves glaucous and glabrous (rarely with a few scattered hairs). |
14 Plant an erect or ascending herb; lower leaves simple, upper leaves simple to 2-6-foliolate; [of dry limestone glades, endemic to wc. VA] |
14 Plant a climbing vine; all leaves generally compound, often 6-10-foliolate; [of various habitats, ranging from sw. VA, KY, TN, GA, and FL westwards]. |
15 Leaf blade thin in texture; secondary and tertiary veins impressed rather than raised on the upper leaflet surface |
15 Leaf blade leathery in texture; secondary and tertiary veins forming a prominently raised reticulum on the upper leaflet surface. |
16 Outer surface of sepals purplish-red or bluish-lavender towards the base and greenish or cream towards the tips; leaflets mostly ovate to elliptic, the base rounded to subcordate, the apex usually obtuse; [Interior Highlands of AR, MO, and OK and Interior Low Plateau of KY, TN, and AL] |
16 Outer surface of sepals either bright scarlet red or yellowish-cream; leaflets mostly ovate to nearly circular in outline, the base mostly subcordate to deeply cordate, the apex often shallowly notched; [TX]. |
17 Sepals yellowish-cream (sometimes lightly tinged with lilac); stamens densely and uniformly pubescent; [Carrizo Sands of ne. TX] |
17 Sepals bright scarlet red; stamens neither densely nor uniformly pubescent; [Edwards Plateau and northeastwards into the Lampasas Cutplain of c. TX] |
13 Lower surface of leaves not glaucous, pubescent (rarely nearly glabrous). |
18 Plants erect, to 2-3 (-5) dm tall, forming clonal patches by underground rhizomes; leaflets linear- lanceolate, averaging ca. 10× as long as wide |
18 Plants viny, sprawling or climbing, the stems usually over 1 m long, not rhizomatous- clonal; leaflets generally broader. |
19 Leaves coriaceous, the secondary and tertiary veins forming prominent reticulations on the upper surface. |
20 Leaf blade coarsely reticulate-veined, the ultimate closed areoles often > 2 mm long in the longer dimension, the tertiary and quaternary veins not prominently raised; achene beak sparsely pubescent to silky, with ascending or appressed hairs |
20 Leaf blade finely reticulate-veined, the ultimate closed areoles mostly < 2 mm long in the longest dimension, the tertiary and quaternary veins often prominently raised; achene beak plumose, with spreading hairs |
19 Leaves membranous to subcoriaceous, the secondary and tertiary veins forming faint, indistinct reticulations on the upper surface. |
21 Sepals 2.5-5 cm long, the tips widely spreading, the upper margins thin, crisped, expanded (to 6 mm wide); sepal surfaces glabrous; [widespread, but mainly Coastal Plain] |
21 Sepals XX-YY cm long, the tips reflexed, the upper margins thick, not expanded; sepal surcaes glabrous to variously hairy; [widespread, but especially inland provinces]. |
22 Principal leaves at mid-stem mostly pinnate, pubescent, slightly coriaceous with raised secondary and tertiary veins; inflorescence solitary in leaf axils, or cymose paniculate (1-3 flowered); sepals rarely solidly colored, sepals light pink, white, or bicolored; fruit compact; achene body orbicular in outline, the achene tails short recurvate; [open habitats (glades, barrens, blackbelt prairie remnants) over limestone] |
22 Principal leaves at mid-stem pinnately trifoliate, glabrous or glaucescent, membranous without raised secondary or tertiary veins; inflorescence solitary, terminal, or cymose- paniculate (3-7 flowered); sepals cherry red, magenta pink, or dusky purple; fruit less compact; achene body elliptical in outline, the achene tails long recurvate; [forested systems, forest/woodland ecotones, and grasslands] |