Sarcodum Lour., Fl. Cochinch. 2: 462 (1790)

Compton, James A., Schrire, Brian D., Koenyves 3, Kalman, Forest, Felix, Malakasi, Panagiota, Sawai Mattapha, & Sirichamorn, Yotsawate, 2019, The Callerya Group redefined and Tribe Wisterieae (Fabaceae) emended based on morphology and data from nuclear and chloroplast DNA sequences, PhytoKeys 125, pp. 1-112 : 31-32

2. Sarcodum Lour., Fl. Cochinch. 2: 462 (1790)

Diagnosis.

The three species of Sarcodum are most closely allied to Endosamara and Sigmoidala but the genus is easily distinguished from the other two by the presence of bracteoles subtending the calyces (absent in Endosamara and Sigmoidala ) and the smaller leaflets (0.3 –2(– 2.5) cm wide in Sarcodum vs. (2 –)2.5– 7 cm wide in Endosamara and Sigmoidala ). Sarcodum , moreover, has leafy racemose inflorescences as opposed to the robust, erect panicles found in Endosamara and Sigmoidala . The back of the standard in Sarcodum and Endosamara is glabrous while that of Sigmoidala is densely pubescent. Sarcodum has fleshy botuliform pods that become woody on drying with oblate seeds borne in septate chambers while the seeds of Sigmoidala are flattened, ellipsoid and those of Endosamara are oblong, surrounded by a papery endocarp. The most widespread species S. scandens has leaves with between 17 and 45 narrowly elliptic leaflets - the most numerous in the tribe - each terminating in a short mucro.

Type species.

Sarcodum scandens Lour.

Genus description.

Three species of scandent twining vines scrambling over shrubs reaching 5-10 m. Stems grey-green when young, terete, densely pubescent, mature stems dark green becoming rusty brown, glabrous. Leaves with 9-45 leaflets, evergreen, often spotted with tannin deposits, sericeous when mature, imparipinnate, rachis 6-19 cm long. Stipules 3-12 mm long, linear-lanceolate, persistent. Stipels 3-6 mm long, linear, persistent. Leaflets 0.8-4.5 × 0.3-2.5 cm, elliptic, grey-green sericeous above and densely white sericeous below, apex rounded, mucronate, mucro c. 1.5-2 mm (retuse in S. bicolor ), margins entire, base rounded. Inflorescence of erect leafy axillary and terminal racemes 3-12 cm long, peduncle densely silvery sericeous. Flowers 6-19 mm long, emerging from November - April. Floral bracts 6-20 mm long, caducous, densely pubescent, narrowly deltoid or ovate-deltoid apex acute or long acuminate. Bracteoles at base of calyx 2-7 mm long. Pedicels 4-12 mm long, densely pubescent. Calyx 3 × 5 mm, broadly campanulate, green or pink, sericeous externally, five lobed, upper 2 lobes ± connate, lower 3 lobes 1-3 mm long, acute. Standard 10-13 × 6-8 mm, ovate, inner surface glabrous, pink or pinkish-lilac, nectar guide broad, dark yellow, back of standard glabrous, apex acute. Callosities of boss type. Wing petals 8-13 × 3 mm, glabrous, much shorter than or subequal to the keel, each narrowly semi-pandurate, slightly curved upwards at the apex; free from the keel, basal claws 1-4 mm long. Keel petals 13 × 4 mm, glabrous, united into a falcate, navicular cup, apex acute and somewhat reflexed. Stamens diadelphous, nine fused together, the vexillary one free, all curved upwards at apex. Ovary glabrous, style glabrous, 3-4 mm long, curved upwards at apex, stigma punctate. Pods 3.5-5 × 0.7-1.2 cm, green, botuliform, dehiscent, gently torulose, surface glabrous, black and hard when dry, internally septate. Seeds 4-10, ellipsoid or oblong, 5-7.5 × 3.5-5 × 2.5-4.5 mm, oblong, rounded at each end, hilum central, broadly elliptic 2-2.5 × 1 mm.

Distribution.

China; Indonesia; Laos; Philippines; Solomon Islands; Vietnam.

Etymology.

sarcos = Gk fleshy.

Habitat.

All three species are climbing and scrambling vines growing in low thicket from sea level to 300 m.