2.10. Pontederia valida (G.X.Wang & Nagam.) M.Pell. & C.N.Horn comb. nov.

Monochoria valida G.X.Wang & Nagam., Acta Phytotax. Geobot. 45(1): 41. 1994. Type. CHINA. Hainan: Sanya, Yanglan, fl., 21 Sep 1990, G.X. Wong 901001 (holotype: WH; isotype: KYO!).

Distribution.

Southern China and Thailand.

Taxonomical notes.

Monochoria valida (≡ P. valida) was described by Wang and Nagamasu (1994), being compared to M. elata (≡ P. elata) and M. hastata (≡ P. hastata). These species are morphologically similar, due to their robust rhizomes, petiolate blades hastate to sagittate and posterior division with acuminate apex. However, they can be easily differentiated by inflorescence morphology (inflorescence sessile, many-flowered, not surpassing the leaves and cincinni fascicle-like in P. hastata; inflorescence pedunculate, many-flowered, surpassing the leaves and alternate cincinni in P. valida; inflorescence pedunculate, few-flowered, surpassing the leaves and alternate cincinni in P. elata). Aside from that, leaf morphology is also helpful in species delimitation in this group. Thus, M. valida is here re-established and transferred to Pontederia s.l.