Sohmaea zonata (Miq.) H.Ohashi & K.Ohashi (2018b: 163)

Saisorn, Witsanu & Chantaranothai, Pranom, 2022, A taxonomic revision of two genera, Pleurolobus and Sohmaea (Leguminosae) in Thailand and Indo-China, Phytotaxa 573 (2), pp. 231-246 : 243-244

5. Sohmaea zonata (Miq.) H.Ohashi & K.Ohashi (2018b: 163) .

≡ Desmodium zonatum Miq. (1855: 250) .

Type:— INDONESIA. Java, in het bosch bij den Kampong Tjikoja, S.N. (lectotype L! U0003523 [digital image], designated here) .

≡ Meibomia zonata (Miq.) Kuntze (1891: 198) .

= Desmodium ormocarpoides Moritzi (1846: 5) , non DC. (1825b: 327), nom. illeg. Specimens cited:—without locality, Zollinger 1060 (BM!, G!, G!, G! & P! P02761406).

= Desmodium ormocarpoides DC. var. velutina Prain (1897: 142) . Type:— MALAYSIA. Pahang, Kwala Tembeling, Ridley 2605 (lectotype SING! SING 0243348 , designated here).

= Desmodium shimadai Hayata (1920: 24) . Type :— TAIWAN. Sankakuyu, Shimada 4 (holotype TI!).

Herb, up to 1 m high; stems and twigs terete, glabrescent and more densely hairy on upper part of plant and uncinate hairy. Leaves unifoliolate, subalternately to spirally arranged; stipules narrowly triangular, 5–7 × 1.5–3 mm, apex long acuminate to attenuate, surface nearly glabrous; petioles 1.3–2.5 cm long, appressed pubescent and uncinate hairy. Leaflets: stipels narrowly triangular, 4–5 × 0.5 mm, apex long acuminate to pointed, surface glabrescent, margin not fimbriate; petiolules 2.5–3 mm, glabrescent to appressed pubescent and uncinate hairy; leaf blade lanceolate to narrowly lanceolate, 4–10 × 1.5–4.5 cm, apex attenuate, base obtuse, margin entire to slightly undulate, upper surface glabrous or uncinate hairy on mid- and lateral veins, lower surface densely soft pubescent and uncinate hairy; lateral veins 8–9 per side. Inflorescences 10–15 cm long, terminal or axillary; rachis sparsely straight and densely uncinate. Primary bract narrowly ovate, 4–4.5 × 1 mm, apex long acuminate to attenuate, surface pubescent and uncinate hairy, conspicuously veined, enclosing 5-immature flowers and secondary bract. Secondary bract narrowly ovate to narrowly triangular, 2–2.5 × 0.5 mm, pubescent. Flowers ca. 6 mm long, 5-flowered fascicles; bracteole 1, oblong to linear, ca. 1 mm long, hairy; pedicels 4–5.5 mm long, densely uncinate and sparsely straight hairy. Calyx light green, 3–3.5 mm long, base cuneate; outside densely pubescent and minutely uncinate, inside glabrous, tube 1–1.5 mm long; teeth 2–2.5 mm long, acuminate to needle-like at the apex, prominently longer than tube length, two lateral teeth shorter than others, lower tooth longest, upper one entire. Corolla : standard obovate, ca. 5 × 3 mm, apex rounded, base attenuate, not auriculate, claw less than 0.5 mm long; wings slightly oblanceolate and curved, ca. 4.2 × 1.5 mm, apex obtuse, base auriculate, ca. 0.2 mm long, claw 1–1.2 mm long; keels slightly curved, ca. 5 × 1.2 mm, prominently longer than wings, apex very shortly beaked, base shortly auriculate, claw ca. 2 mm long. Stamens 5–6 mm long. Gynoecium ca. 6.5 mm long; ovary oblong, laterally compressed, pubescent, very shortly stipitate, 7-ovulate. Pods dark brown, sessile, indehiscent, 5–8-articulate, compressed, ca. 8 cm long, ca. 2.5 mm wide, surface densely uncinate, not reticulate-patterned (but longitudinal striate), both sutures less constricted between articles; isthmus ca. 3/5 as broad as the pod; articles very narrowly elliptic, 12–23 mm long; fruiting pedicels 6–9 mm long, puberulous and uncinate hairy; calyx not persistent. Seeds transversely oblong.

Distribution:— Sri Lanka, India, Southern China, Thailand, Malaysia, Indonesia, Philippines, and Solomon Islands.

Ecology:—On foot hills and limestone mountains; 200–300 m elev.

Phenology:—Flowering in May–August. Fruiting in June–October.

Notes:—This species is similar to Sohmaea teres but it is differed by having longer petiole and longer and larger pod article. The protologue of Desmodium ormocarpoides DC. var. velutina Prain was based on two specimens originated from Malaysia, Ridley 2605 (SING) and Ridley 7295 (SING). The first one is selected here as a lectotype because it has more perfect condition than the latter.

Specimens examined:— THAILAND. Nakhon Sawan: Ban Hu Kwang , 7 Nov. 1920, Kerr 4537 ( ABD) ; Phetchabun: Nam Nao National Park , 29 Mar. 2015, Saisorn 391 ( KKU) ; Chanthaburi: Nam Tok Taka Mao, north of Chanthaburi, 25 Aug. 1972, Larsen et al. 31993 ( AAU, BKF, C, K, L, P, SING) & Pong Nam Ron, Khao Soi Dao Wildlife Sanctuary , 26 Nov. 1979, Shimizu et al. T-23687 ( KYO) ; Nakhon Si Thammarat: Thung Song , 22 July 1929, Rabil 151 ( BK, BM, C, K, L, P) ; Yala: Bannang Sata , 27 July 1923, Kerr 7362 ( BM) ; LAOS. Khammouane: Khoun Kham, Kong Lo village , 6 Sept. 2012, Sengvilai & Phonesack KK.0437 ( NHL) & Ta Viang , ca. 400 m, 5 Apr. 1931, Kerr 20905 ( BK, BM, K) ; VIETNAM. Lang Son: Chi Lang , 5 Oct. 1964, Khoi 1901 (HN-4 sheets) & Chi Lang, Loc P-2205 ( HNU) ; Thanh Hoa: Ba Thuoc, Co Lung Municipality , 50–100 m, 16 Sept. 2003, Averyanov et al. HAL2951 ( HN) .