Flemingia ferruginea Wall. ex Benth. (1852: 245)

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 : 33-34

21. Flemingia ferruginea Wall. ex Benth. (1852: 245) . Type:— MYANMAR. Tong Dong, 1826, Wall.Cat. 5750 (Holotype, K-

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Shrublets, erect, ca. 30–50 cm tall. Young branchlets densely tawny pubescent and sparsely lenticels when old. Petiole 2.5–4 cm long, pubescent, grooved or not winged. Stipules lanceolate, caducous. Leaves digitately 3-foliolate; terminal leaflet blade rhomboid, lateral leaflet blade obliquely ovate, 5–8 cm long, 3–4.5 cm wide, apex acute or shortly mucronate, base rounded or cuneate; adaxially glabrescent, abaxially densely tawny pubescent; basal veins 3, unequal, reaching upwards to two-three of the length of the lamina, lateral veins pinnate, 5–6 pairs. Inflorescence racemose, axillary, solitary; inflorescence axis equalling the petiole or shorter, tawny villous; bracts lanceolate-ovate, very caducous. Flowers purple; pedicel with a small sessile. Calyx tube ca. 2 mm long, tawny villous; calyx lobes unequal linear, as long as the tube, rather thick. Corolla purple, ca. 4–5 mm long. Pods oblong-elliptic, ca. 5 mm long, puberulous, sparsely dotted with black resin glands. Seeds 1 or 2, black, suborbicular.

Ecology and phenology: — Flemingia ferruginea grows in secondary forest and grassland. Flowering and fruiting from January to May.

Distribution: — Myanmar and China.

Notes: — Gagnepain (1916) originally described a new variety, namely F. ferruginea var. eglandulosa from Laos. Later Nguyen (1979), in his treatment of Flemingia in Flore du Cambodge Laos et du Vietn-nam, synosymized this variety under F. ferruginea . However, careful examination of the specimen type of that species at P revealed that those actually belong to Flemingia kerrii Craib , a previously known species from Thailand. Therefore, F. ferruginea is here exclused from Laos. Recently, Sa & Gilbert (2010), in Flora of China, synonymized this species under F. macrophylla . However, F. ferruginea cleary differs from the latter by having parsely lenticels on the old branchlets, densly twany pubescent on the abaxial leaf surface; inflorescence axis is as long as the petiole or slightly longer; and calyx lobes are linear, falcate and longer than the corolla. These morphological characters are most similar to those of F. wightiana Graham ex Wight & Arnott (1834: 242) , an endemic species to India. Further studies are necessary to clarify the delimitation of these two species.

From recent examination on the Flemingia collections at Chinese herbaria (KUN, PE, HITBC, IBSC) indicated that the majority of specimens belonging to F. latifolia Benth or F. grahamiana Wight were misidentified as F. ferruginea .

Representative specimens: —MYANAMR. Pome: S.Kurs 2527 (CAL); Makhaye: Dr. King’s collector 342 (CAL). Madalay: Kyaukpadaung, Popa Mountain Park, T.T.Aye & K.M.Htwe 021363 (KUN). CHINA. R.C.Qin 22148 (KUN). Yunnan: Shiping, Yangwu to Shiping, H.Wang 6357 (HITBC).