2.5. Pontederia elata (Ridl.) M.Pell. & C.N.Horn comb. nov.

Monochoria hastata var. elata (Ridl.) Backer, Fl. Males. 4: 258. 1951.

Monochoria elata Ridl., J. Straits Branch Roy. Asiat. Soc. 79: 99. 1918. Lectotype (designated by Cook 1989). MALAYSIA. Kedah: Jenun, fl., fr., 19 Nov 1915, M. Haniff 1208 (K barcode K000291970!; isolectotypes: BM barcode BM000958428!, K barcode K000291971!).

Distribution.

From Myanmar to Malaysia, Thailand and China.

Taxonomical notes.

Monochoria elata (≡ P. elata) was treated by Cook (1989) as well as Guofang and Horn (2000) as an accepted name, but subsequent floras (e.g. Wang et al. 2004) and online databases (eMonocot 2010; The Plant List 2013; Govaerts 2018; Tropicos.org 2018) have either considered M. elata a synonym of M. hastata (≡ P. hastata) or as a variety of the latter. Nonetheless, both species can be easily differentiated based on the petiolate ornamentation, the width of the petiolate leaf-blades, length of their inflorescences and number of flowers per inflorescence. Thus, M. elata is here re-established and transferred to Pontederia s.l.