TETRANDRIA. TETRAGYNIA. Potamogeton. 



2li 



P. Leaves bristle-shaped, parallel, near together, pointing pectina'tum 



2 



ways. 



E. hot. 323-Lob. k. i. 79C-Ger. em. 828. 4-Pet. 5. 13 



PluL 216. 5. 



I 



Flowers 5 or 6 on each fruit-stalk. Mr. Stackhouse. Stem 

 cylindrical. Leaves flatted. Bloss. whitish. 



Fennel-leaved Pondvoeed. Rivers and ponds. [R. Waveneyv 

 Woodward. Entirely filling up a pond at Pendarvis, Cornwall* 

 Mr. Stackhouse.] P. May — July. 



P. Leaves strap-shaped, alternate, distinct; thebase sheath- mari'num. 



ing the stem. 



FL dan. 186-Vaill. 32. 5-//. ox. v. 2$ 9* at p. 596. 



The Stipule not distinct in this, as in the other species, but 

 the leaves fixed to them. Linn. Leaves growing from the 

 sheaths, which are slightly forked at the extremity as in P. pec- 

 tinatum. In stagnant salt water ditches the whole plant is 

 shorter ; the branches and leaves closer and more frequent. In 

 running water, whether salt or fresh, it grows to a vast length, 

 and the branches and leaves are farther asunder, but in both cases 

 preserve their parallelism. Spike long ; with sitting flowers, 

 growing mostly in interrupted whirls. Fl. dan. 186 more ex- 

 actly resembles our fresh than salt water plants, though quoted 

 in Syst. Veget. for P. marinum. Woodward. Leaves scarcely a 

 Hne broad. Pollich. In quite fresh water it becomes the P. 

 pecttnatum. Mr. Crowe, Mr. Woodward. 



Sea Pondvoeed. Salt water ditches. [Near Yarmouth. Mr. 



Woodward. In the Skern, near Darlington, a fresh water 



rivulet. Mr. Robson.] 



P. Huds. July, August. 



m 



P. Leaves strap -spear-shaped, alternate, sitting, broader gramin'eum 



than the stipulae. 



Fl. dan. 222-Ray 4. 3. 



The leaves at the base of the fruit-stalks opposite. Stipule 

 v ?ry numerous and large. Hall. Fl. dan. and Ray are both 

 referred to by Linnaeus and Haller, but Mr. Lightf. has very 



remarked 



Ray. I 



suspect they will turn out to be 2 species. x Ray 4. 3, is the fig. 

 referred to in the Sp. pi. and with which my specimens corre- 

 spond. Stipule much narrower than the leaves, and so as easily 

 *o escape the attention of a common artist ; rather strap-shaped, 

 Muntish, und set close, as in Ray's figure ; not spear-shaped, ta- 

 pering to a point, toothed, and at a considerable distance from each 



^r, as in that of the Fl. dan. Ribs i ; very finely serraud- 

 Stokes. Leaves mostly serrulated upwards. 



p2 



