446 RANUNCULACEAE 
1. Thalictrum clavatum DC. Foliage glabrous. Stems branching, 1.5-6 dm. high, 
nearly leafless : leaves mainly basal, 5-10 cm. long, biternate ; leaflets thin, stalked, oval, 
ovate, or the terminal obovate-cuneate, with 3 main lobes and a few secondary ones, 
the margins not revolute: inflorescence cymose: flowers perfect: filaments spatulate 
and petal-like : anthers oblong, blunt: achenes spreading, rather scimitar-shaped, the body 
longer than the stipe, narrowed at each end, flattened, tipped with the minute stigma. 
About mountain brooks, Virginia and West Virginia to Georgia and Alabama. Spring and early 
summer. 
2. Thalictrum miràbile Small. Foliage glabrous, bright green. Stems erect, 1-3 
dm. tall, wiry, dichotomously branched above: leaves various, the basal usually ter- 
nately compound, with petioles about 2 em. long ; upper leaves gradually more simple and 
shorter-petioled ; leaflets suborbicular or orbicular-reniform, 2-3 cm. broad, very thin, 
delicately nerved, glaucescent beneath, broadly crenate or shallowly crenate-lobed, truncate 
or subcordate at the base, longer than the petioles: peduncles hair-like: flowers white: 
sepals spatulate or rhombic-spatulate, fully 1.5 mm. long: filaments fully 2 mm. long, petal- 
like by an abrupt thickening about the middle: achenes spreading at right angles to the 
peduncle, the body plump, about 2 mm. long, acute, not depressed along the upper side, 
shorter than the filiform stalk. 
On sandstone bluffs, Little Mountain, northern Alabama. Spring. 
3. Thalictrum débile Buckl. Foliage glabrous. Roots tuber-like, clustered : stems 
simple or sparingly branched, procumbent, 1-4 dm. long, slender: leaves delicate, 
with slender petioles ; leaflets thin, suborbicular to obovate, 0.5-1.5 cm. broad, more or 
less distinctly 3-lobed, the lobes entire or shallowy toothed: flowers dioecious, few, mostly 
in pairs, short-pedicelled : sepals cuneate or oblong-spatulate, 2-2.5 mm. long: stamens 
7-11: filaments slender, shorter than the mucronulate anthers: achenes 1-6, oblong, ses- 
sile, 3.5-4 mm. long, prominently 6—8-ribbed. 
In rich woods in the mountains, Georgia and Alabama. Spring. 
4. Thalictrum Texànum (A. Gray) Small Foliage glabrous, somewhat glaucous. 
Roots fusiform, clustered: stems often branched at the base, the branches wiry, erect or as- 
cending, 1-3 dm. tall: leaves rather numerous, with filiform petioles ; leaflets firm, cune- 
ate to reniform, 2-7 mm. broad, entire, cleft or lobed: flowers several, slender-pedicelled : 
achenes narrowly oblong, 3-3.5 mm. long, prominently 6-8-ribbed, slender-beaked. [T. 
debile var. Texanum A. Gray.] 
On moist prairies, near Houston, Texas. Early spring. 
5. Thalictrum dioicum L. Foliage glabrous. Roots not yellow: stems erect, 3-6 
dm. high, slender, leafy: leaves ample; blades 3-4-ternate ; leaflets thin, pale beneath, 
orbicular or broader, often cordate and the terminal one somewhat cuneate, 5-9-lobed : 
flowers dioecious, greenish, drooping or spreading : panicle elongated, of numerous lateral 
corymbs or umbel-like corymbs : filaments longer than the sepals: anthers linear, blunt, 
longer than the filaments : stigma elongated: achenes ovoid or oval, sessile or minutely 
stipitate, with rounded ribs, much longer than the style. 
In woods, Labrador and Anticosti to Saskatchewan, in the mountains to Georgia and Alabama, 
and Missouri. Spring. 
6. Thalictrum coriàceum ( Britton) Small. Foliage glabrous. Rootstocks and roots 
bright yellow : stems 1-1.5 m. high, striate, paniculately branched above : leaves ample ; 
blades 3-4-ternate, short-petioled, the lower petioles expanded at the base into broad stip- 
ule-like appendages ; leaflets obovate or reniform-orbicular, rather leathery, nearly white 
beneath, usually deeply and sharply incised, the nerves prominent on the lower surface: 
flowers dioecious ; staminate nearly white, the anthers linear, subulate-tipped, longer than 
the filiform filaments ; pistillate flowers purple : achenes oblong-ovoid, subacute, stipitate, 
sharply ribbed, longer than the persistent style. 
_ In open woods, mountains of southwestern Virginia to Kentucky, Tennessee and North Carolina. 
Spring and early summer. 
7. Thalictrum caulophylloides Small. Foliage deep green, glabrous. Stems erect, 
6-12 dm. tall: leaves 2-5 dm. long, spreading, with long petioles ; leaflets firm, broadly 
oval to suborbicular in outline, mainly broader than long, 4-9 em. in diameter, glaucous and 
prominently nerved beneath, cordate or truncate, 3-5-lobed above the middle, the lobes apic- 
ulate; petiolules slender, 5-30 mm. long: pedicels 8-20 mm. long, wire-like : achenes 
elliptic, 6 mm. long, sharply ribbed, contracted into stipes 1.5-2 mm. long, each tipped 
with the persistent club-shaped style. 
On mountain slopes, Tennessee. Spring and summer. 
