Pleurolobus flexuosus H. Ohashi & K. Ohashi 2018
Creators: name: Saisorn, Witsanu
name: Chantaranothai, Pranom
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Fabales
Fabaceae
Pleurolobus
Pleurolobus flexuosus

description: 1. Pleurolobus flexuosus (Wallich 1831: 195 ex Bentham 1852: 224) H.Ohashi & K. Ohashi (2018c: 386).   
 ≡ Desmodium flexuosum Wall. ex Benth.   
 Type:— MYANMAR. Montes Prome, 1826, Wallich 5691 (lectotype K-W! K001121777, designated here, isolectotypes G!-2 sheets, BM!, K! K000858866, CAL, n.v.).   
 ≡ Meibomia flexuosa (Wall. ex Benth.) Kuntze (1891: 198).   
 Creeping herb; stems and twigs angular or subterete, brown pubescent. Leaves subalternately or spirally arranged; stipules, narrowly triangular, 5–10 × 1–1.5 mm, apex acuminate, surface long pubescent; petioles (0.3–) 1.5–3.5 cm long, densely erect pubescent. Leaflet coriaceous; stipels narrowly triangular to filiform, 2–5 mm long, apex pointed, surface glabrescent to pubescent; petiolules 1–3 mm, densely pubescent; leaf blade cordate, broadly obovate to broadly elliptic, 1.5–6.5 × 1.5–6 cm, apex ±acute to rounded or shallowly emarginate, base ±cordate, margin entire, upper surface glabrescent, lower surface appressed pubescent, denser than upper surface; lateral veins 7–9 per side. Inflorescences pseudoracemose or paniculate, with a few branches, 5–15 cm long; rachis and rachilla densely pubescent and minutely uncinate. Primary bract 3–7 × 0.5 mm, apex pointed, surface long pubescent, enclosing 2-immature flowers and secondary bract. Secondary bract persistent, narrowly triangular, ca. 1 × 0.3 mm, pubescent. Flowers 2–2.5 mm long, 2-flowered fascicles; pedicels 2–2.5 mm long, with uncinate hairs. Calyx 1.5–2 mm long, base obtuse; outside white pubescent, tube ca. 1 mm long; teeth 4, 0.8–1 mm long, ±equal to tube length, upper tooth shallowly divided, less than 0.2 mm long. Corolla: standard broadly obovate, ca. 3 × 3 mm, apex shallowly emarginate, base attenuate, entire or slightly auriculate at base, claw very short; wings ca. 3 × 1.2 mm, ±equal to the keel petals, apex obtuse, base not auriculate, claw ca. 0.5 mm long; keels curved, ca. 3.2 × 1.5 mm, the broadest part near the apex, apex obtuse, base not auriculate, claw ca. 1.5 mm long. Stamens ca. 3 mm long. Gynoecium ca. 3.5 mm long; ovary appressed pubescent; style ca. 1.5 mm long, glabrescent; stigma minutely capitate. Pods dark brown to black, 3–4-articulate, straight, 7–10 × 2–2.5 mm, surface sparsely uncinate, inconspicuously reticulate-patterned, upper suture undulate, lower suture more constricted than upper suture, ca. 1 mm deep; isthmus 2/5 as broad as the pod; articles obliquely ovate or subcircular, ca. 3 mm long; pod usually sessile or shortly stipitate, ca. 0.5 mm long; fruiting pedicels 2.5–3 mm long, with uncinate hairs. Seeds transversely elliptic.   
 Distribution:— Myanmar, Thailand, and Cambodia.   
 Ecology:—In teak plantation, with bamboo and deciduous forests; 30–400 m elev.   
 Phenology:—Flowering in November. Fruiting in November–February.   
 Notes:— Two specimens, Maxwell 06-874 (CMUB) and Pierre 1006 (P) are newly recorded for Cambodia. Desmodium flexuosum Wall. ex Benth. was validly published. Five original specimens were examined at BM, G, K, and K-W by authors and one duplicate was recorded by Ohashi (1973). All specimens are from the same gathering and in a perfect condition. A specimen kept at K-W (K001121777) is selected here as the lectotype because it is well preserved in Wallich’s collection at Kew.   
 Specimens examined:— THAILAND. Chiang Mai: Doi Suthep, 1100 m, 17 Oct. 1910, Kerr 1480 (ABD, BM, C, K-2 sheets, L, P), Doi Suthep, 1200 m, 28 Nov. 1911, Kerr 1480B (BM, E, K, L, P) & Doi Suthep-Pui National Park, 350 m, 19 Dec. 1989, Maxwell 89-1568 (CMU, E, L); Lampang: Chae Son, Ban Sa, 400 m, 7 Nov. 2008, Maxwell 08-198 (CMUB); CAMBODIA. Kratie: Sambour, Mekong River, 30 m, 15 Nov. 2006, Maxwell 06-874 (CMUB) & May 1870, Pierre 1006 (G, P).
description: Published as part of Saisorn, Witsanu & Chantaranothai, Pranom, 2022, A taxonomic revision of two genera, Pleurolobus and Sohmaea (Leguminosae) in Thailand and Indo-China, pp. 231-246 in Phytotaxa 573 (2) on pages 232-233, DOI: 10.11646/phytotaxa.573.2.4, http://zenodo.org/record/7349951