Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne (1867).djvu/284

11. P. natans Potamogeton natans, L. Native. British type. Area C, N, D. Range 1.

Common in ponds in the low country, ascending in Coquetdale above Rothbury, 150 yards.

12. P. oblongus Potamogeton oblonus, Viv. Native. British type. Area C, N, D. Range 1, 2.

Frequent in peaty pools, especially amongst the moors, ascending in Teesdale to 500 yards.

13. P. plantagineus Potamogeton plantagineus, Ducr. Native. English type. Area C, D. Range 1.

In a pond near Dunstanbro' (Professor Oliver! T.). Ditches at Alnmouth (T.). Hell Kettles near Croft (F. B.). The three stations mentioned under "P. fluitans" in the Flora belong one each to this, P. oblongus and P. rufescens.

2. RUPPIA, L.

1. R. maritima Ruppia maritima, L. Native. Maritime. British type. Area C, N, D. Range 1.

Salt water ditches, rare. Warren Mills, in the Coquet near Warkworth, Meggy's Burn, Tees mouth, &c.

3. ZANNICHELLIA, L.

1. Z. palustris Zannichellia palustris, L. Native. British type. Area C, N, D. Range 1.

Ditches and slow streams, frequent. Var. pedicellata, Fries. at the mouth of Meggy's Burn, Willington Burn, &c.

4. ZOSTERA, L.

1. Z. marina Zostera marina, L. Native. Maritime. British type. Area C, N, D. Range 1.

All along the coast in the sea, but not very frequent.