Crotalaria umbellata Wight & Arnott (1834: 191)

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

43. Crotalaria umbellata Wight & Arnott (1834: 191) . Crotalaria nana var. umbellata (Wight & Arn.) Ansari (1991: 445) . Type (lectotype designated here):— INDIA. Tamil Nadu, Dindygul Hills, 1 January 1832, Wallich 5383 (lectotype K-W K001120734!, isolectotypes BR n.v., E00174382!, P02754602!).

Herb, erect, 6–15 cm high, much branched nearly from the base; young branches terete, brown pubescent. Leaves simple. Stipules minute, caducous. Petioles 0.3–1.5 mm long, brown pubescent. Lamina oblong or oblanceolate, 0.7–4 × 0.2–0.6 cm, base obtuse, apex acute, margin entire, brown puberulous upper, brown pubescent lower; lateral veins inconspicuous. Inflorescences terminal or axillary, capitate racemes, 1–1.5 cm long; peduncle 8–13 mm long, silvery pubescent. Bracts narrowly linear, 1.3–4.7 mm long, caducous. Pedicels 2–3 mm long, brown pubescent. Bracteoles inserted on the calyx tube, narrowly linear, 2.5–3 mm long, persistent. Calyx 4–5 mm long, campanulate, bilabiate; tube 2–3.5 mm long; lobes triangular, 1.5–2 mm long, glabrous inside, brown pubescent outside. Corolla yellow. Standard: claw 0.6–0.8 mm long, glabrous, margin white tomentose; blade broadly elliptic, 3.8–4 × 3.5–3.8 mm, base obtuse, apex rounded, margin glabrous. Wings: claw 0.3–0.5 mm long, glabrous; blade oblong, 4–4.5 × 0.8–1 mm, base oblique, apex obtuse, margin glabrous. Keel: claw 0.2–0.3 mm long, glabrous; blade ovate, 5–5.3 × 2–2.3 mm, beak spirally twisted, base oblique, apex attenuate, margin glabrous. Stamens: filaments fused for proximal 0.5–1.2 mm, free for distal 2–3.8 mm; anthers either narrowly linear, 0.9–1 mm long or oblong, 0.4–0.5 mm long. Ovary sessile, elliptic, 1.3–1.5 mm long, glabrous; style 3.5–3.8 mm long, adaxially white puberulous in a single line along the distal edge, abaxially glabrous. Pods sessile, elliptic, 5–7 × 1.5–2 cm, brown-black, glabrous. Seeds reniform, 1–2 × 1–1.5 mm, brown.

Representative specimens: — CAMBODIA. Banteay Meanchey: Svay Chek , 22 October 1927, Poilane 14334 ( P) . THAILAND. Khon Kaen : Khon Kaen University , 28 December 1964, Chermsirivathana 219 ( BK) . Nakhon Ratchasima: Bua Yai , 31 October 1931, Put 4219 ( BK, BM, K) . Rayong: Klaeng , 10 October 2008, Wessumritt & Norsaengsri 25 ( QBG) . Sukhothai: Sukhothai District, 6 November 1971, Maxwell 71-726 ( AAU, BK) . VIETNAM: No locality, no date, Anon. s.n. ( P) .

Distribution: —Asia ( India, Sri Lanka, Thailand, Cambodia, Vietnam). ( Figure 26 ).

Ecology: —Sandy roadsides or open places, elevation 28–200 m.

Notes: —This species has been consistently confused with Crotalaria nana , but differs in being a short erect herb with short inflorescences and caducous bracts. Two collections, Wallich 5383 (BR n.v., E!, K!, P!) and Wight 700 (E!, NY n.v.) from India are mentioned in the original description of C. umbellata . Wallich 5383 (K!) is chosen as lectotype because it is well preserved and has three duplicates as isolectotypes.

Figures

FIGURE 26. Distribution map of Crotalaria trichotoma and C. umbellata in continental Southeast Asia.