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8. P. coMPRESsus. Flat-stalked Pond-weed. June — July. % 
* Pond at St. Trinien’s, near Richmond. Ponds at Castle Howard. 
Near Beverley. 
9. P. cuspiDATus. Pointed-leaved Pond- weed. 
In a rivulet at Hovingham. (Teesdale.) It has not been found there 
of late years. 
10. P. GRAMiNEus. Grassv Pond-weed. July — August. If. 
In the river Derwent at Crambe bridge. In the ponds at Castle 
Howard. 
11. P. pusiLLus. Small Pond- weed. July. 7/ 
Ponds near Beverley. Ponds at St. Trinien’s, near Richmond. 
Norton ings, opposite Old Malton Abbey. 
12. P. PECTiNATUS. Fennel-leaved Pond- weed. July. 7/ 
In the Rye, Foss, and Derwent. 
The floating leaves of the different species afford an agreeable shade to fish, and are the habitation and 
food of Hydrocampa Potamogeton, (the Brown China Mark.) 
2. ZOSTERA. 
1 . Z. MARINA. Grass-wrack. August — September. 7/ 
Ditches in the marshes at Coatham, near Redcar. 
Thrown on our shores by the tide ; mounds or walls are built with it to oppose the incroachment of the 
sea. Buildings are thatched with the green leaves, which will endure upwards of a century. The minute 
Conferva xostericola. Viva plantaginea, Berkeleya fragilis, and the rare Exilaria Jiahellata, are para- 
sitic on this plant. 
3. RUPPIA. 
1. R. MARiTiMA. Tassel Pond- weed. August — September. 7/ 
Salt water ditches in the marshes at Coatham. 
Named in honour of the German Physician, Henry Ruppius, author of “ Flora Jenensis.” This plant, 
(like Vallisneria spiralis, an inhabitant of rivers in the south of Europe,) lengthens or contracts its fruit- 
stalk according to the greater or less depth of water ; and, assuming a spiral form, the flowers and fruit 
are thus borne above the surface, sinking afterwards to deposit the seeds at the bottom. The fructifica- 
tion is highly curious and interesting, and is beautifully illustrated in Flora Londinensis. 
4. ZANNICHELLIA. 
1. Z. PALusTRis. Horned Pond- weed. July. O 
Bolton beck, near Skeeby. In a brook near Gilling beck. 
A variety with the anthers 2, 3, and 4 celled and lobed, and the stigmas 
toothed constituting the Z. dentata of Willdenow, is found near Richmond, by 
Mr. James Ward, Jun. 
Named after the eminent Venetian Apothecary, Zannichelli, who published a History of Plants, and 
flourished about 1702. 
O 
