9. Thalictrum debile Buckley, Amer. J. Sci. Arts. 45: 175. 1843.
Roots brownish, fusiform-tuberous with dried ribs. Stems reclining, branched and flexible proximally, 10-40 cm, glabrous. Leaves: proximal cauline leaves petiolate, 1-3×-ternately compound; distal cauline leaves petiolate or sessile, 1-2×-ternately compound or simple. Leaf blade: leaflets ovate or obovate to reniform or orbiculate, apically shallowly to deeply 3-7-lobed, rarely undivided, 4-15 mm wide, surfaces glabrous. Inflorescences terminal and axillary, panicles, elongate, few flowered. Flowers: sepals whitish, lanceolate to obovate, 1.5-2.7 mm; filaments colored, not white, 1.5-2 mm; anthers 1.7-2.5 mm, mucronate; stigma color unknown. Achenes 1-6, not reflexed, nearly sessile; stipe 0.1-0.3 mm; body oblong to elliptic-lanceolate, not compressed, 3-3.7 × 0.7-1.2 mm, glabrous, prominently 6-8-veined, veins not anastomosing; beak 1.3-2 mm.
Flowering in early spring (Mar-Apr). Rich, rocky, limestone woods, often in wet, alluvial soil; of conservation concern; 50-300 m; Ala., Ga., Miss.
Thalictrum debile is closely related to T . arkansanum and T . texanum . The distinctions among the three species should be further studied.