Thalictrum clavatum de Candolle var. filamentosum (Maximowicz) Finet & Gagnepain.

Plants 15--35 cm tall, glabrous. Roots tuberous, globose. Stems erect. Basal leaf 1, 15--25 cm; petiole 7--13 cm; leaf blade 2-ternate, (4.5--)6.5--9 cm; leaflet blade ovate or broadly so, herbaceous, base rounded or cordate, margin inconspicuously 3-lobed; veins flat on both surfaces. Cauline leaves 2, opposite, sessile, simple, ovate or broadly so. Inflorescence flat topped, 1.5--5.5 cm. Sepals early deciduous, white, oblong, ca. 2 × 0.5 mm. Stamens 5--8 mm; filament base filiform, apex oblanceolate, 3--4 × as broad as anther; anther elliptic, ca. 0.6 mm. Carpels 2--5; style obscure. Achene stipe slender. Fl. May.

Forests, scrub. Heilongjiang, Jilin [Russia].