Crotalaria occulta Graham ex Bentham (1843: 565)

Ninkaew, Sakuntala, Balslev, Henrik, Pornpongrungrueng, Pimwadee & Chantaranothai, Pranom, 2017, Crotalaria L. (Fabaceae: Faboideae) in continental Southeast Asia, Phytotaxa 320 (1), pp. 448-450 : 448-450

30. Crotalaria occulta Graham ex Bentham (1843: 565) . Type:— INDIA. Sylhet: De Silva 5360 (holotype K001120672 !).

Herb, erect, 40–80 cm high; young branches terete, brown pubescent. Leaves simple. Stipules absent. Petioles 0.5–0.8 mm long, brown pubescent. Lamina obovate or oblanceolate, 0.4–4.5 × 0.3–1.2 cm, base cuneate, apex acute, margin entire, sparsely pilose upper, pilose lower; lateral veins inconspicuous. Inflorescences terminal, lax open racemes, 2–11 cm long; peduncle 0.2–1.2 cm long, brown pubescent. Bracts narrowly linear, 2–4 mm long, persistent. Pedicels 2–5 mm long, brown pubescent. Bracteoles inserted distally on the pedicel, narrowly linear, 1–1.5 mm long, caducous. Calyx 1.2–1.5 cm long, campanulate, bilabiate; tube 4–5 mm long; lobes triangular, 8–10 mm long, glabrous inside, brown pubescent outside. Corolla purple. Standard: claw 1.8–2 mm long, white tomentose above and along the margin, glabrous below; blade broadly obovate, 10–12 × 10–13 mm, base obtuse, apex obtuse, margin glabrous. Wings: claw 1.8–2 mm long, glabrous; blade obovate, 10–13 × 3–5 mm, base oblique, apex obtuse, margin glabrous. Keel: claw 1.5–1.8 mm long, glabrous, margin white pubescent; blade lanceolate, 10–12 × 4.5–5 mm, beak spirally twisted, base oblique, apex attenuate, margin white tomentose. Stamens: filaments fused for proximal 2–4 mm, free for distal 2–5 mm; anthers either narrowly linear, 2.5–2.8 mm long or oblong, 0.6–0.8 mm long. Ovary sessile, oblong, 5–6 mm long, glabrous; style 11–12 mm long, adaxially white pubescent in a single line along the distal edge, abaxially glabrous. Pods glabrous. Seeds not seen.

Representative specimens: — LAOS. Xieng Khouang: 2 November 1920, Poilane 2215 ( P) .

Distribution: —Asia ( India, China, Laos). ( Figure 19 ).

Ecology: —Elevation ca. 900 m.

Notes: — Crotalaria occulta is distinguished by its purple flower, lack of stipules, its pilose obovate or oblanceolate leaves, claw margin of standard which is tomentose and the lanceolate keel blades.

Figures

FIGURE 19. Distribution map of Crotalaria occulta and C. pallida in continental Southeast Asia.