282 



GENUS il. POTAMOGETON. 



Vetrandria Tetjpa. Sex: Syst: 



Deriv. Erom Potamos, a river, and Geiton, near, alluding to tie 

 habitat of the species. 



Gen. Chak. Flo-wers androgynous, spiked, naked, placed together 

 by eights and bearing a pseudo-hermaphrodite flower, 4-gynous : 4- 

 sepaled, 4-androus, from them four central ones females (pistils), 

 ebracteate, distinct, 4 males at the circumference, reduced to solitary 

 stamens, altematiag -with the females "(pistila), each supported by a 

 broadly spathulate bract ; stamen inserted at the short claw of the 

 bract : anther sub-sessile, ovate-cordate, emarginately 2-lobed at the 

 apex, 2-celled, dehiscing extrorsely lengthways : ovary sessile, I- 

 ovuled : ovule affixed to the ventral suture below the apex : style 

 ter m inal, short or wanting: stigma introrsely oblique, papillose, 

 entire: fruit drupaceous, lenticular-compressed at the sides, 1 -seeded, 

 indehiscent : ptrtamen coriaceous, woody, half-2-ceUed : embryo 

 exalbuminous : radicle inferior, opposite the hUum. — Caulescent 

 aquatic herbs, submersed or floating : leaves scattered, distichous, 

 the top ones sometimes, very rarely all opposite, stipulate : stipules 

 connate among themselves, distinct from the petiole or leaf, seldom 

 joined together with the petiole into a sheath: spikes spadix- 

 shaped, peduncled, naked, terminal and axiUary, emerging while in 

 flower. 



(I) P. PEEFOLiAiuM. (Linn.) 

 Idenf. Linn. spec. 182. — Eunth Enum. pi. III. 133. 

 Si/n. P. Loeselii, Roem. and SchuU. syst. III. 508. 

 Engrm. Eng. Bot. t. 168. — Cham, in Linn. II. t. 5 fig. 13. 



Spec. Chae. Stem round, slightly branched; leaves all sub- 

 mersed, of one shaped, sessile, half-stem-clasping with a cordate 

 base, ovate or ovate-lanceolate, obtuse, membranous, pellucid : 

 stipules united into a ■ sheath, embracing the stem : fruit obtusely 

 ■ angled. 



Streams near Dapoorie. 



(2) P. cEisruM. (lAwn./ 

 Ident. Linn. sp. 183. — Kunth. 1. c. — Dalz. Bomb. flor. p. 248. 

 Si/n. P. tuberosum, Roxb.flor. Ind. I. p. 452. — P. serratum, Zam. 

 MigrwB. Engl. Bot. t. 10121.— Elor. Dan. t. 927. 



Spec. Chak. Stem branched, rather compresssd : leaves all sub- 

 mersed, uniform, sessile, oblong-linear, obtuse or shortly acuminate, 



