Crotalaria prostrata Rottler ex Willdenow (1809: 747)

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

34. Crotalaria prostrata Rottler ex Willdenow (1809: 747) . Type :— INDIA. Rottler s.n. (holotype B-W n.v.). seen on Herbarium Berolinense Virtual Herbarium.

Herb, prostrate, 15–25(–30) cm high; young branches terete, brown pubescent. Leaves simple. Stipules absent. Petioles 0.3–1 mm long. Lamina elliptic, 0.5–2 × 0.3–1.3 cm, base subcordate, apex rounded, margin entire, both surfaces brown pubescent; lateral veins inconspicuous. Inflorescences leaf-opposed or axillary, open racemes, 1–4.5 cm long; peduncle 0.4–1.5 cm long, brown pubescent. Bracts narrowly linear, 0.5–1 mm long, persistent. Pedicels 1–2 mm long, brown pubescent. Bracteoles inserted on the calyx tube, narrowly linear, 1–1.5 mm long, persistent. Calyx 4–6 mm long, campanulate, bilabiate; tube ca. 1 mm long; lobes triangular, 3–5 mm long, glabrous inside, brown pubescent outside. Corolla yellow. Standard: claw 0.5–0.8 mm long, glabrous; blade elliptic or obovate, 4–5 × 3–3.3 mm, base obtuse or cuneate, apex rounded or emarginate, margin glabrous. Wings: claw 0.5–0.8 mm long, glabrous; blade oblong, 3.8–4.1 × 1–1.7 mm, base oblique, apex obtuse, margin glabrous. Keel: claw 0.3–0.5 mm long, glabrous; blade ovate, 4–4.1 × 2–2.2 mm, beak spirally twisted, base obtuse, apex attenuate, margin glabrous. Stamens: filaments fused for proximal 1–1.7 mm, free for distal 1.5–2.5 mm; anthers either narrowly linear, 0.4–0.5 mm long or oblong, ca. 0.1 mm long. Ovary sessile, oblong, 2–2.5 mm long, glabrous; style 2.5–3 mm long with dispersed white pubescence. Pods sessile, oblong, 1–1.5 × 0.2–0.3 cm, brown, glabrous. Seeds reniform, 1.2–1.8 × 1–1.3 mm, brown.

Representative specimens: — CAMBODIA. Stung Treng: 13 November 1927, Poilane, 14247 ( P) . MYANMAR. Bago: Pyay (Prome), 1826, Wallich 5419 ( K) . Magway: around 4 miles from Saw , along the roadside between Saw and Kangyi, 14 February 2012, Fujikawa et al. 86675 ( QBG) . THAILAND. Chiang Mai: Om Koi , 30 November 2013, Pongamornkul 3881 ( QBG) . Kalasin: Somdet , 24 October 1975, Sutheesorn & Sangkhachand 3537 ( BK) . Lampang: Thoen , 20 November 2014, Norsaengsri 11669 9 ( QBG) . Phuket: Nai Harn Beach , 14 December 1979, Shimizu et al. T-27266 ( BKF) . VIETNAM. Dak Lak: Ban Me Thuot, Schmid 775 ( K, P) . Lam Dong: Da Lat , 22 October 1940, Poilane 31087 ( K, L, P) . Long An: December 1939, Poilane 30156 ( AAU, K, L, P) .

Distribution: —Asia ( India, Myanmar, China, Thailand, Cambodia, Vietnam), Australia. ( Figure 20 ).

Ecology: —Deciduous forest, elevation 7–1500 m.

Notes: — Crotalaria prostrata could perhaps be confused with C. acicularis with which it has a superficial resemblance, but it lacks stipules. Niyomdham (1978) expected C. prostrata to occur in Thailand and included it in his key but did not give a full account.

Figures

FIGURE 20. Distribution map of Crotalaria perpusilla, C. phyllostachya and C. prostrata in continental Southeast Asia.