不丹紫堇 bu dan zi jin

Herbs, perennial, 30-50 cm tall; stems and petioles of radical leaves attenuate toward base. Storage roots spindle-shaped, 1.5-2 cm. Stems erect, with 2 or 3 leaves and 1-3 branches, naked in lower 1/3. Radical leaves few; petiole 10-14 cm, slender; blade glaucous abaxially, green adaxially, broadly triangular, 7-11 × 7-11 cm, triternate; pinnae with petiolule 2.5-4.5 cm; pinnules with petiolule 0.5-2 cm; segments elliptic-obovate, 1.2-2.2 × 0.5-1.3 cm, entire, obtuse. Cauline leaves: petiole 2-6 cm; blade like radical leaves. Raceme terminal, 2-4 cm; peduncle 3-20 cm; bracts elliptic, 3-6 × 1.5-3 mm, margin entire, apex acute. Pedicel 1.5-3 mm, slender. Sepals nearly orbicular, very small, margin nearly entire. Corolla light blue, lavender, or amaranth; outer petals: limb navicular, acute, without or with very narrow crest; upper petal 25-28 mm; spur arcuately downcurved, cylindric, 16-18 mm; lower petal: limb navicular, central part contracted, basally conspicuously saccate; nectary 1/3-1/2 as long as spur. Stigma quadrate, without basal lobes, with 8 marginal papillae, laterally and in basal corners with geminate papillae. Capsule (immature) narrowly elliptic, ca. 15 × 3 mm; style ca. 2 mm. Fl. and fr. Apr-May.

Forests; 2000-2600 m. SE Xizang (Bomi) [Bhutan, NE India].