Crotalaria dubia Graham ex Bentham 1843
Creators: name: Ninkaew, Sakuntala
name: Balslev, Henrik
name: Pornpongrungrueng, Pimwadee
name: Chantaranothai, Pranom
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Fabales
Fabaceae
Crotalaria
Crotalaria dubia

description: 12. Crotalaria dubia Graham ex Bentham (1843: 568). Type (lectotype designated by Ansari 2008):— INDIA. East India, without exact location; probably Sylhet or Burma, Wallich 5404 (lectotype K000591064!).   
 Herb, erect, 30–50 cm high; young branches terete, brown pubescent. Leaves simple. Stipules narrowly linear, 2–4 mm long, brown pubescent, caducous. Petioles 2–4 mm long, brown pubescent. Lamina obovate or elliptic, 1.2–5.5 × 0.4–3 cm, base cuneate, apex rounded or obtuse, margin entire, both surfaces brown pubescent; lateral veins 5–6 pairs. Inflorescences terminal or axillary, open very dense racemes, 1–5 cm long; peduncle 3–7 mm long, densely brown pubescent. Bracts ovate, 4–7 × 2–3 mm, persistent. Pedicels 1–2 mm long, brown pubescent. Bracteoles inserted distally on the pedicel, ovate, 3–5 × 2–3 mm, persistent. Calyx 6–8 mm long, campanulate, bilabiate; tube 1–2 mm long; lobes triangular, 4–5 × 0.8–1.2 mm, glabrous above, brown pubescent outside. Corolla yellow. Standard: claw 1–1.5 mm long, white tomentose above and along the margin, glabrous below; blade broadly ovate, 4.5–5 × 3–3.5 mm, base cuneate, apex obtuse, margin glabrous. Wings: claw 1–1.2 mm long, glabrous; blade lanceolate, 3.5–5 × 1–1.3 mm, base oblique, apex attenuate, margin glabrous. Keel: claw 1–1.2 mm long, glabrous; blade ovate, 4.5–5 × 2.3–2.5 mm, beak spirally twisted, base cuneate with white pubescence, apex attenuate, margin glabrous. Stamens: filaments fused for proximal 2–2.3 mm, free for distal 1.5–2.3 mm; anthers either narrowly linear, ca. 1 mm long or elliptic, ca. 0.2 mm long. Ovary sessile, elliptic or oblong, 1.4–1.6 mm long, glabrous; style 4.5–5 mm long, adaxially densely white pubescent in a single line along the distal edge, abaxially glabrous. Pods sessile, oblong, 5–7 × 2.5–3 mm, brown-black, glabrous. Seeds harp-shaped, 1–1.5 × 1.6–1.8 mm, yellow-brown.   
 Representative specimens: — MYANMAR. Chin State: along the roadside between Saw and Mindat, Natma Taung National Park, 1 March 2013, Sangvirotjanaphat 91167 (QBG). THAILAND: Chiang Mai: Doi Chiang Dao Wildlife Sanctuary, 20 December 2014, Ninkaew 307 (KKU). Chiang Rai: Khun Chae National Park, 30 December 1997, Maxwell 97-1544 (CMUB). Nan: Bo Kluea, 21 February 2014, Ninkaew 252 (KKU). Phrae: Mae Kham Mi, 5 January 1972, Beusekom et al. 4646 (BKF). VIETNAM. Gia Lai: Dak Doa, 28 October 1978, Loc & Nghia P 3711 (HNU).   
 Distribution: —Asia (India, China, Thailand, Vietnam). (Figure 9).   
 Ecology: —Roadsides, elevation 160–900 m.   
 Notes: — Crotalaria dubia is distinct from all other species of Crotalaria in having dense open inflorescences with ovate bracts, wings with attenuate apex and the keel with glabrous margins.
description: Published as part of Ninkaew, Sakuntala, Balslev, Henrik, Pornpongrungrueng, Pimwadee & Chantaranothai, Pranom, 2017, Crotalaria L. (Fabaceae: Faboideae) in continental Southeast Asia, pp. 448-450 in Phytotaxa 320 (1) on pages 448-450, DOI: 10.11646/phytotaxa.320.1.1, http://zenodo.org/record/13699110