296. Corydalis angusta Z. Y. Su & Lidén, Fl. China. 7: 406. 2008.
细距紫堇 xi ju zi jin
Type: China. Sichuan: Ebian (O-pien) Xian, under woods, alt. 2000 m, 18 May 1932, T. T. Yü 822 (holotype, KUN; isotype, A).
Corydalis angusta a speciebus affinibus racemis subspicatis multifloris, corollis minoribus atque calcaribus brevioribus angustioribus longe distat.
Paratype: Medicine Identification Centre, Health Bureau of Xichang District 0506 (SM).
Corydalis angustiflora C. Y. Wu, p.p. (excluding type).
Herbs, perennial, 40-60 cm tall, glabrous. Rhizome columnar, 4-9 × 1-1.5 cm, clad with densely imbricate fleshy scales and petiolar bases in 2 rows. Stems few, erect, from below few-leaved apical rosette, branched above, with 4 or 5 leaves in upper 1/2, sometimes a single long-stalked leaf in lower 1/2. Radical leaves: petiole 12-22 cm, base broadly sheathed; blade glaucous abaxially, dark green adaxially, ovate-triangular, 4-8 × 4-8 cm, biternate; primary leaflets with petiolule 1-2 cm, ultimate leaflets shortly stalked, deeply ternatisect; lobes again shallowly to deeply 3-7-divided; lobules broadly lanceolate to oblong. Cauline leaves: lower petiole 3-4(-10) cm, upper ca. 1 cm; blade like radical leaves, but progressively smaller upward. Racemes long and narrow, 15-28-flowered, 7-10 cm; bracts oblanceolate, 3-7 mm, entire; lowermost bract sometimes larger and slightly divided. Pedicel filiform, 6-9 mm. Sepals ovate, 0.5-1 mm, finely dentate. Corolla purple to blue; inner petals whitish. Outer petals narrow, acute, with short narrow crest; upper petal 15-17 mm; spur cylindric or slightly tapering, very narrow, upturned from base, straight, 9-10 mm; nectary absent; lower petal ca. 11 mm, with narrow claw and narrowly rhombic acute limb; inner petals ca. 10 mm. Ovary narrowly lanceolate; ovules 7; style 2.5-3 mm; stigma square, simple marginal apical papillae 4; geminate papillae lateral and on well-developed basal lobes. Fl. May-Jun.
● Understories of mixed forests; ca. 2000 m. SW Sichuan (Ebian, Xichang: Beimu Shan).
Corydalis angusta differs substantially from other species in the section by the combination of branched leafy stems and small flowers, with thin straight spur, in many-flowered racemes.
The specific epithet refers to the narrow corolla spur, from Latin angustus ("narrow").