PoraMocEToN. ] NAIADACE. 313 
i. A. monostachyon, Linn. f. Suppl. (1781) 214; Roxb. Fl. 
Ind, ti, 210; F. B. I. vi, 564; Waitt, BE. D.; Prain, Beng. Pl, 
1122 ; Cooke Fl. Bomb. ti, 837. A. natans (L.) Engl. and Krause, 
Pflanzenr. iv, 13, p. 11. Vern. Jechu. 
Rootstock }-4 in. diam. stoloniferous, edible. Leaves 24-8 in. long by 
3-14 in. floating, oblong or linear-oblong, base cordate, acute or 
rounded at the apex, with 3-5 nerves on either side of the midrib 
and distinct cross nerves, petiole slender, subtrigonous much longer 
than the blade. Spike solitary densely flowered. Sepals obovate, 
zs in. long about as long as the stamens. Stamens 6, anthers bluish- 
purple. Carpels 3. Follicles exceeding the sepals, seeds 4-8, longi- 
tudinally ribbed. 
Throughout the plains (Royle.) Like most water plants this has 
been seldom collected, I have seen none from the Gangetic Plain. 
Distris.: Behar (Hope), S. India (Wight), N. Australia. 
2. A. crispum, Thunb. Nov. Gen, iv (1781) 78; F. B. I. vi, 564 ; 
Prain, Beng. Pl. 1122. A. undulatum, Roxb. Fl. Ind. ii, 271, 
Rootstock 4-} in. diam. stoloniferous, edible. Leaves mostly sub-~ 
merged, blade linear-lanceolate or oblong, 4-6 inches long or longer, 
3-7 longitudinal nerves and numerous fine cross nerves, petiole 
compressed, shorter than the blade. Spike solitary, the flowers dense 
at first but ultimately rather lax. Sepals oblong, 4 inch long, about 
twice as long as the stamens. Stamens 6. Carpels usually 3. Seeds 
oblong usually 1, sometimes 2, smooth. 
The plains, Saharanpur. Disrris.: Bengal, Burma. 
2. POTAMOGETON, Linn.; Fl. Brit. Ind. vi, 565; P 
Ascherson and P. Grebner, Pflanzenreich, IV, 11. 
Annual or perennial aquatic herbs, rootstock creeping. Leaves 
submerged or the upper floating, opposite or alternate, stipules 
intrapetiolar. Flowers bisexual, small, greenish, in spikes on an 
axillary or leaf-opposed peduncle arising from a membranous 
sheath, bracts 0. Perianth of 4 concave green valvate segments 
(sometimes regarded as outgrowths of the connectives). Stamens 
4, anthers sessile at the base of the perianth-segments, didymous, 
Carpels 4, free, sessile; ovule one, campylotropous from the inner 
angle of the carpel; stigma subsessile or decurrent, persistent, 
