Sohmaea teres (Wallich 1831: 196 ex Bentham 1852: 225 ) 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 : 241-242

4. Sohmaea teres (Wallich 1831: 196 ex Bentham 1852: 225) H.Ohashi & K.Ohashi (2018b: 163) . Fig. 2C–D .

≡ Desmodium teres Wallich ex Bentham Type:— MYANMAR. Taong Dong, Wallich 5694 (lectotype K-W! K001121790 , designated by Rafidah et al. (2020), isolectotypes BM! BM000946774, CAL, n.v., G!, K! K000858870, K-W! K001121791).

≡ Meibomia teres (Wall. ex Benth.) Kuntze (1891: 198) .

= Desmodium zonatum Meeuwen (1961: 97) , non Miq. (1855: 250). Specimen cited:— Dorgeh 1755 (L, n.v.), fide Ohashi (2004).

Herb, up to 2 m high; stems and twigs terete, sparsely to densely uncinate hairy. Leaves unifoliolate, alternately arranged; stipules narrowly triangular, 5–12 × 2–3 mm, apex long acuminate to caudate, surface glabrescent; petioles 0.3–0.8 cm long, ascending pubescent and minutely uncinate. Leaflets: stipels narrowly triangular, 2–5 × 0.5–1 mm, apex long acuminate, surface glabrescent, margin not fimbriate; petiolules 1.5–3 mm, ascending pubescent and uncinate hairy; leaf blade lanceolate to narrowly lanceolate or oblong, (3–)9–20 × (0.5–) 2.5–7 cm, apex attenuate, base obtuse, margin entire, upper surface nearly glabrous or sparsely uncinate hairy, with straight hairs on mid- and lateral veins, lower surface spreading uncinate hairy, with straight hairs on mid- and lateral veins; lateral veins 9–14 per side. Inflorescences 10–40 cm long, terminal or axillary; rachis densely uncinate hairy. Primary bract narrowly ovate, 3.5–4 × 1–1.5 mm, apex long acuminate to attenuate, surface pubescent, conspicuously veined, enclosing 5-immature flowers and secondary bract. Secondary bract narrowly ovate to narrowly triangular, 1.5–2 × 0.5 mm, pubescent. Flowers 6–7 mm long, 5-flowered fascicles; bracteoles absent; pedicels 4–5 mm long, densely uncinate and straight hairy (on lower half part). Calyx yellowish green, ca. 4 mm long, base cuneate; outside ascending pubescent and minutely uncinate, inside glabrescent, tube ca. 1.5 mm long; teeth 2–3 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 white, wings and keels violet to blue; standard broadly obovate to oblanceolate, 4.5–8 × 3.5–5.2 mm, apex obtuse to rounded, base attenuate, not auriculate, claw 0.3–1 mm long; wings slightly oblong, 3.5–6 × 1–2 mm, apex obtuse, base auriculate, ca. 0.3 × 0.5 mm, claw 0.5–1 mm long; keels slightly curved, 4–7 × 1–1.5 mm, prominently longer than wings, apex acute to slightly obtuse, base shortly auriculate, claw ca. 2.5 mm long. Stamens 4–7.5 mm long; anthers ellipsoid, ca. 0.3 × 0.2 mm. Gynoecium 4.5–9 mm long; ovary oblong, laterally compressed, pubescent, stipitate, 0.5–1 mm long, 10–13-ovulate; style 1.5–3 mm long, pubescent; stigma minutely capitate. Pods light brown, indehiscent, 8–11-articulate, subterete, 4–6.5 cm long, 1–1.5 mm wide, surface densely uncinate, not reticulate-patterned (but longitudinal striate), both sutures less constricted between articles and thickened; isthmus ca. 4/5 as broad as the pod; articles narrowly oblong to linear, 5–6 mm long; pod stipe 1.5–2 mm long, glabrescent; fruiting pedicels 5–7 mm long, ascending pubescent and uncinate hairy. Seeds brown, transversely oblong, 4.5–5 × 1 mm, ca. 0.7 mm thick.

Distribution:— Myanmar, Thailand, Malaysia, and Indonesia.

Ecology:—In sunny places of limestone mountain and evergreen, dry evergreen, and mixed deciduous forests; 50–700 m elev.

Phenology:—Flowering in September–November. Fruiting in October–January.

Notes:— Sohmaea teres is a new record species for Cambodia.

Specimens examined:— THAILAND. Chiang Mai: Mae Rim, QBG, BGO. Staff 4828 ( QBG-2 sheets), Doi Chiang Dao , 480 m, 21 Oct. 1955, Garrett 1460 ( K, L, P-2 sheets), Doi Chiang Dao , 600–1300 m, 25 Sept. 1971, Murata et al. T-14911 ( KYO) , Doi Chiang Dao , 600–1300 m, 25 Sept. 1971, Murata et al. T-14936 ( KYO) , Chiang Dao, Ban Bing Kong , 500 m, 29 Oct. 1987, Maxwell 87-1304 ( CMU, L) , Doi Suthep , 630 m, 17 Oct. 1999, Srapratet 24 ( CMUB) , Fang, Doi Pha Hom Pok National Park , 21 Dec. 2014, Saisorn 352 ( KKU) , Mae Rim , QSBG, 860 m, 13 Nov. 2014, Tanming 732 ( QBG) & Chiang Dao, Tham Chiang Dao , 350 m, 15 Feb. 1958, SØrensen et al. 1137 ( C) ; Chiang Rai: Doi Pha Hom Pok , 700 m, 15 Sept. 1967, Iwatsuki et al. T-9724 ( KYO) & Pan, Doi Luang National Park , 610 m, 3 Nov. 2015, Muangyen 214 ( QBG) ; Phayao: Mae Chai, Doi Luang National Park , 800 m, 4 Nov. 2015, Muangyen 318 ( QBG) , Doi Luang National Park , 600 m, 4 Nov. 2015, Muangyen 327 ( QBG) & Mueang Phayao, Doi Luang National Park , 575–625 m, 25 Sept. 1997, Petrmitr 123 ( BKF, CMUB) ; Nan: Tham Pha Tok , 250 m, 16 Nov. 1993, Larsen et al. 44405 ( AAU) ; Lampang: Chae Hom , 325 m, 26 Oct. 2012, Maxwell 12-279 ( CMUB, QBG) , en route from Pang La to Huai Tak, 350 m, 24 Sept. 1967, Shimizu et al. T-10752 ( BKF, KYO) & without locality, 250 m, 22 Nov. 1922, Winit 811 ( ABD, BK, K) ; Sukhothai: Si Satchanalai, Ban Mae San , 17 Nov. 2015, Maknoi 8391 ( QBG) & Ban Mae San , 28 Jan. 2016, Maknoi 8514 ( QBG) ; Nakhon Sawan: Ban Na Kluay , 50 m, 7 Nov. 1924, Kerr 4537 ( ABD, BK, BM, E, K) ; Phetchabun: Nam Nao National Park , 3 Nov. 2013, Mattapha 448 ( KKU) & Nam Nao National Park , 18 Oct. 2004, Mattapha 696 (KKU-2 sheets) ; Loei: Pha Nok Khao , 250–350 m, 6 Dec. 1970, Charoenphol et al. 4564 ( AAU, BKF, C) & Wat Tham Pha Sawan, 381 m, 14 Nov. 2011, Clark et al. 240 ( K, QBG) ; Khon Kaen: Phu Pha Man National Park , 25 Oct. 2007, Norsaengsri & Lakoet 2807 ( QBG) , Phu Pha Man National Park , 410.6 m, 22 Nov. 2007, Norsaengsri & Lakoet 3069 ( QBG) , Phu Pha Man National Park , 467 m, 24 Dec. 2011, Norsaengsri & Tathana 8403 ( QBG) , Wiang Kao, Phu Wiang National Park , 11 Nov. 2014, Saisorn et al. 294 ( KKU) , Wiang Kao, Phu Wiang National Park , 15 Feb. 2015, Saisorn 376 ( KKU) , Chum Phae, Dong Lan , 300 m, 22 Nov. 1958, Smitinand 4919 ( BKF, L) & Chum Phae, Dong Lan , 400 m, 22 Dec. 1958, SØrensen et al. 6122 ( C) ; Nakhon Ratchasima: Pak Chong , 600–650 m, 20 Nov. 1982, Koyama et al. T-30147 ( KYO) , Pak Chong , 700–730 m, Koyama et al. T-30094 ( KYO) & without locality, 18 Dec. 1962, Phengklai 584 ( C, K, L) ; Kanchanaburi: Wang Po , 26 Oct. 1969, Kasem 648 ( BK, L, SING) , Srisawat , 580–600 m, 26 Nov. 1982, Koyama et al. T-30304 ( KYO) , Sai Yok , Mahidol University Kanchanaburi Campus , 225 m, 20 Dec. 2005, Maxwell 05-739 ( CMUB) , Si Sawat, Ban Khao Lek , 500–600 m, 21 Oct. 1994, Nisit 94102118 ( BK) , Si Sawat, Ban Khao Kaeng Khaep , 500 m, 2 Nov. 1979, Shimizu et al. T-21399 ( BKF, KYO, L) , Si Sawat, Erawan National Park , 100–300 m, 3 Nov. 1979, Shimizu et al. T-21540 ( BKF, KYO) , Si Sawat, Erawan National Park , 100–300 m, 3 Nov. 1979, Shimizu et al. T-21567 ( KYO) , Sai Yok , 160 m, 6 Nov. 1979, Shimizu et al. T-21760 ( BKF, KYO) , Sai Yok, Near Sai Yok Arboretum , 160 m, 6 Nov. 1979, Shimizu et al. T-21829 ( KYO) & Si Sawat , 150 m, 5 Nov. 1971, van Beusekom et al. 3413 ( BKF, C, K, KYO, L-2sheets, P) ; Prachuap Khiri Khan: Kui Buri, Sam Roi Yot , 23 Oct. 1973, Sutheesorn 2703 ( BK) ; Lop Buri: Chai Badan , 280 m, 4 Dec. 1982, Koyama & Terao T-30595 ( BKF, KYO) & Subchampa Hill , 170–190 m, 19 Nov. 1984, Murata et al. T-50933 ( BKF, KYO) ; Saraburi: Muek Lek , 200 m, 10 Nov. 1924, Marcan 1867 ( ABD, BK, BM, KKU) ; Chon Buri: Si Racha, Khao Khiao , 300 m, 18 Dec. 1974, Maxwell 74-1077 ( BK) & Si Racha, Khao Khiao , 100 m, 20 Oct. 1975, Maxwell 75-1052 ( AAU, BK, L) ; Chanthaburi: Pong Nam Ron , 700 m, 11 Oct. 1955, Sangkhachand 528 ( BKF, L) , Pong Nam Ron, Ban Thalee , 200 m, 24 Oct. 1956, Smitinand 3616 ( BKF) & without locality, 200 m, 28 Nov. 1956, Smitinand 3648 ( BKF, L) ; LAOS. Luang Prabang: Massie s.n (Dy Phone et al., 1994); CAMBODIA . Mondulkiri: Sen Monorom , 527 m, 5 Nov. 2016, Yahara et al. 7382 ( FU) ; VIETNAM. Annam: Ca-na, Phanrang , 500 m, 22 Nov. 1923, Poilane 8652 (P-2 sheets) .

Figures

FIGURE 2. A.–B. Sohmaea laxiflora: A. Habit; B. Infructescence; C.–D. S. teres: C. Habit; D. Inflorescence with flowers and immature pods. Photos A.–B. by the first author; C.–D. by T. Srisuk.