Limnophila hippuridoides Philcox, sp. nov.

27. Limnophila hippuridoides Philcox, sp. nov. L. aromaticae (Lam.)

(Fig. I, p. 149 & Map. 8, p. 147.)

MALAYA. Malacca, 16 Dec. 1867, Maingay 3077 (K). Perak, Larut, in still water, 500 ft. [152 m.], June 1883, King's Collector 4398 (K, holotype). This species is quite unique in the genus in so far as it is the only one outside section Limnophila to be adapted for a truly aquatic life. This is shown by the presence of whorls of numerous undivided, linear to linear-lanceolate submerged leaves; clearly different from those on the aerial flowering stems. These submerged leaves are also unique, in being undivided, for in all other species adapted for aquatic conditions they are capillary-multifid.

At first it was suspected that this plant was an aquatic form of L. aromatica, but the author has seen no evidence of heterophylly in the many specimens of that species he has studied. He has also tried unsuccessfully to induce this state in plants of L. aromatica under cultivation by lengthy and total immersion in water. Bearing these facts in mind, it has been decided to describe this plant as a new species allied to L. aromatica, from which it also differs by the much smaller, and externally glabrous corolla.