Chinese Water Chestnut

"Chinese water-chestnut" was, probably, formerly cultivated in Pakistan. Formal taxonomic rank sometimes given to cultivated races is based on E. tuberosa Schultes, Mantissa 2: 86. 1824. Schultes refers to Roxburgh, Fl. Indica (1820) [= Scirpus tuberosus Roxburgh, Hort. Bengal. 6. 1814 nom. nudum?, non Desf. 1798.

Perennial, forming small tufts, sterile stems to 140 cm. Rhizome short, emitting white stolons which end in a spherical, edible tuber. Stem 3-5 mm diam., terete, with conspicuous septae 2-5 cm apart, often with less pronounced septa between. Sheaths absent (in specimens studied). Spike 20-50 x 7-10 mm; two basal glumes green, lower almost completely clasping, upper opposite, smaller; glumes 6.5-8 mm, finally yellowish grey, cymbiform, with clear mid-nerve, other nerves obscure, margin scarious, c.0.5 mm wide, apex rounded. Perianth bristles 6-8, rigid, yellowish, c. equalling nut; stamens 3; stigmas 2 or 3. Nut 2-2.3 x 1.6-1.8 mm (without stylopodium), thickly bi-convex, spherical or obovoid, brown or yellow-brown, shiny, surface finely reticulate, with c. 0.5 mm stipe, apical annulus bordering style base; stylopodium c. 1 x 0.8 mm. conical, flat or shallowly trigonous, brown or dark brown, often with remains of whole style attached.

Afriea, India, Indo-China, China, Japan, Malaysia, N. Australia.

Distribution: Africa, India, S. China, Japan, Taiwan, Malaysia, Australia, Pacific Islands; frequently cultivated.

200 m

Fl. Per.: September.

In shallow water, ponds etc.

Andropogon dulce Burm.f., Fl. Ind.: 219. 1768; E. plantaginea (Retz.) Roem. & Schult., Syst. Veg. 2: 150. 1817; C. B. Clarke, l.c. 625. 1893; Scirpus plantagineus Retz., Obs. Bot. 5: 14. 1789; Blake, Proc. Roy. Soc. Queensland 50: Pl. VIII, figs. 6-9. 1939. Tang & Wang, Fl. Reipubl. Pop. Sinicae 11: Pl. 18: figs. 1-5. 1961. Roxb., Pl. Coromandel, 3,25: Tab. 231. 1819.