Flemingia langbiangensis T.V.Do, B.Xu & X.F.Gao (2019: 41)

Do, Truong Van & Gao, Xin-Fen, 2020, Taxonomic revision of the genus Flemingia (Leguminosae) from Indo-Chinese floristic region, Phytotaxa 429 (1), pp. 1-38 : 30-31

18. Flemingia langbiangensis T.V.Do, B.Xu & X.F.Gao (2019: 41) . Type:— VIETNAM. Lam Dong: Da Lat city, Ta Nung protected forest area, elev. 820 m, 8 November 2017, Do Van Truong VNMN-XTBG 160 (holotype VNMN!; isotype CDBI!)

Erect shrub about 1.2 m tall. Branchlets terete, slightly grooved, with conspicuous lenticels, glabrescent. Petioles 5–7 cm long, narrowly winged, pubescent, adaxially grooved, petiolules 4–6 mm long, densely villous of grey indumentum. Stipules lanceolate, 1.0– 1.3 cm long, margin densely trichomes, outside densely brown silky, inside glabrous, obviously striate, caducous. Leaves digitately 3-foliolate; leaflets leathery with sunken venation, glabrous except for brownish glands on both surfaces, less on the upper, dense on the lower; leaflets venation prominent below with some indumentum; terminal leaflet rhombic or obovate, rarely elliptic, 9–11 cm long, 5–6 cm wide; basal veins 3, equal, external ones reaching upwards to more than three-fourth of the length of the leaflet lamina, lateral veins pinnate, 6–8 pairs, base cuneate, apex acuminate or slightly cuspidate; lateral leaflets unequal, oblique–ovate or elliptic–lanceolate, 7–11 cm long, 4–5 cm wide, basal veins 3, unequal, slender one reaching upwards to one-third or a half of the length of the leaflet lamina, thicker one reaching upwards to more than two-third of the length of the lamina leaf, lateral veins pinnate, 6–8 pairs, base oblique and apex acuminate. Inflorescence racemose with flowers condensed at apex, subcapitate-like, axillary or terminal, solitary or cluster of 2–4 racemes; inflorescence axis conspicuous, 2.5–4.0 cm long, straight, densely brownish villous; bracts broadly ovate, about half of the calyx length, being 5–6 mm long, 4–5 mm wide, base truncate, apex obtuse to rounded, margin densely pubescent, outside densely silky of brown trichomes, glabrous inside with well-marked striation and black glands, caducous. Flowers subsessile, 1.2–1.5 cm long; pedicel maximum 1 mm long, densely villous. Calyx tube 3–4 mm long, calyx lobes slightly longer than the tube, with five unequal lobes, lanceolate, upper subequally 4-lobed, straight, 6–7 mm long, 1.5–2 mm wide, lower 1-lobed, broadest and longest, strongly curved, 8–9 mm long, 2–2.5 mm wide, outside densely dark-brown silky, inside densely appressed brownish pubescent, margin densely pubescent. Corolla as long as the calyx or slightly longer, glabrous, standard broadly ovate to orbicular, 7–8 mm long, 4–5 mm wide, greenish-pinkish with obviously parallel striation, clawed, 3–4 mm long, apex cuspidate, base tapering to the claw with short auricles, ca. 1 mm long, margin entire; wings obovate, shorter than standard and keel, 5–6 mm long, 2.5–3 mm wide, pink, clawed, 3–3.5 mm long, apex acute, base tapering to the claw with short auricles, margin entire; keel falcate, wider than wings, 7–8 mm long, 3–3.5 mm wide, pinkish-green, clawed, 3.5–4 mm long, acute at apex, tapering to the claw with extremely short auricles at base, 0.5 mm long, 1 mm wide, margin entire. Stamens diadelphous; staminal tube 9–10 mm long, thick, pubescent at lower half; filaments 1.5–2 mm long, glabrous; vexillary stamen free, 10–11 mm long, thin, glabrous; anther oblong 1–1.2 mm long, 0.5 mm wide, glabrous. Ovary elliptic, subsessile, densely pubescent of white trichomes, 3–3.5 mm long, 2-ovuled; style long, filiform, 1.3–1.4 cm long, densely whitish pubescent on the lower two-thirds; stigma capitate. Pods turgid, ellipsoid, 10–11 mm long, 5–6 mm wide, densely brownish pubescent, without glands, oblique and shortly beaked at apex. Seeds usually 2, black, subglobose, 2–2.5 mm diam.

Iconography citation: — Do et al. (2019: 42–43), figures 1–2.

Ecology and phenology: — Flemingia langbiangensis is only known and probably endemic from Langbiang Plateau in Lam Dong province, southern Vietnam. The species grows in disturbed meadows, roadsides, forest margins and under the canopy of pine forest ( Pinus kesiya ) at alt. 700–1050 m. This new species has been observed in flower from November to December, and fruiting from December to late January.

Distribution: —Endemic to Vietnam.

Notes: — Flemingia langbiangensis is morphologically similar to Flemingia latifolia , F. ferruginea , and F. macrophylla , but readily distinguished from all three species by the combination of some morphological characters of branchlets, abaxial leaf surface, racemes, shape and size of bracts, size of calyx, colour of corolla, and size of pods ( Do et al. 2019).

Representative specimens: — VIETNAM. Lam Dong: Da Lat city, along Gold stream, elevation 1500 m, 28 December 1982, LX-VN 1000 (HN).