Pleurolobus J.St.-Hil. (1812: 192)

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 : 232

1. Pleurolobus J.St.-Hil. (1812: 192) .

Type species: P. gangeticus (L. 1753: 746) J.St.-Hil. (1812: 192) .

Desmodium sect. Heteroloma Benth. (1852: 224) [unranked] Latifolia Benth. (1852: 224), pro parte. Type species: D. gangeticum (L.) DC. (1825b: 327) (lectotype, designated by Ohashi et al. (2018b)).

Herbs. Leaves unifoliolate, petiolate, stipulate; leaflet petiolulate, stipellate, lateral veins reaching the margin. Inflorescences terminal or axillary; primary bract 1, persistent, narrowly triangular; secondary bract 1, persistent. Flowers papilionaceous, pedicellate; bracteole absent; calyx connate with 4 teeth; corolla 5-merous, with 1 standard, 2 wings and 2 connate keels; stamens 10, diadelphous; ovary unicarpellate, oblong, laterally compressed. Pods leguminous, with a deep, constricted article; seeds rim-arillate.

Six species distribute in tropical Africa, Madagascar, Mascarene Islands, Asia, and Australia. One species is indigenous to Myanmar, Thailand, and Cambodia. Another species is native to those three countries, Laos, and Vietnam.

Key to the species

1. Primary bracts bearing 2-fascicled flowers. Pedicels less than 3 mm long. Flowers 2–2.5 mm long; stamens less than 4.5 mm long...............................................................................................................................................................................1. P. flexuosus

1. Primary bracts bearing 3–4-fascicled flowers. Pedicels at least 3 mm long. Flowers ca. 4 mm long; stamens 4.5–5 mm long ......... ..................................................................................................................................................................................... 2 P. gangeticus