



213 TETRANDRIA. TETRAGYNIA. Ruppia. 



Grass-leaded Pondvoeed. Slow streams and ditches. Binsey 

 common* Ditches by the road side going to Port Meadow, Oxon. 

 Sibthorpe. [River Skern, near Darlington. Mr. Robson.] 



P. July, 



seta'ceum. P. Leaves spear-shaped, opposite, tapering to a point. 



In peaty ditches in Lancashire, P. July, Aug. 



pusil'lum, P. Leaves strap-shaped, opposite and alternate, distinct, 



expanding from the base : stem cylindrical. 



E. hot. 2\5-Vaill. 32. 4-P*/. 5. 11. 



Leaves alternate ; but those at the base of the fruit-stalks op- 

 posite. Neck, as is the case in all the species I have examined 

 even where the other leaves are alternate. Dr. Stokes. Whole 

 plant extremely slender. Stem much branched, scored. Leaves 

 very narrow, pointed, extremely expanding at the base, some- 

 times almost bent back. Stipule broader than the leaves, short, 

 membranaceous. Spike short. Flowers on fruit-stalks. Wood- 

 ward. Leaves rather longer than the joints of the stem, not at 

 all sheathing it. Fruit -stalks sheathed at the base by 2 concave, 

 skinny, spear-shaped scales, which Dr. Smith observes are sti- 

 ulae, being found withiri the base of all the leaves, but are pro- 

 ably calculated to answer the purposes both of stipule and also 

 of floral leaves as lateral fruit-stalks rise from within them. 

 Spikes terminating, nearly globular, about 8 flowers in each. 



Small Pondvueed. Ponds in clayey soil. [About Tarn worth, 

 Warwickshire.] A. Linn. P. Huds. June — Aug* 



RUFPI A. Cal. none : Moss, none : seeds 4, on pe- 



dicles. 



mari'tima. R. 



■Afi 



and 





Park. 1289. 5-Ligbtf. 8. \-Fructif. Raj 6. 1. *//. 1&- 



Flowers on each fruit-stalk, from 1 to 4, though commonly 

 2, one terminating, and one sitting. Stamens, ger mens and seeds, 

 4 in each flower. This plant when not in fruit, very much re- 

 semblcs Potamogeton marinum. Mr. Robson. Leaves alternate, 

 very long and slender. Stems thread-shaped. 



Tassel Pond<weed. Sea TasseLgrass. Salt water ditches. [Near 



Yarmouth. Mr. Woodward. Cornwall, Mr. Stackhouse. 



Mr 



f 





j 



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