446 BANUNCULACEAE 



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 mirabile 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 cm. 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 dbile 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 Texanum (A. Gray) Small. Foliage glabrous, somewhat glaucous. 

 Hoots 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 coriaceum(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 cm. 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. 



