REPORT FOR 1914. 



167 



Naias flexilis R. tfe S. Estliwaite Water, v.-c. 69b, August 14, 

 1914. The dominant species in a remarkable association (see Hydrilla 

 verticillata). Although the species fruits freely it is so abundant 

 that it must have been established here for some considerable time. — 

 W. H. Pearsall. " An excellent addition to the English flora. Mr 

 Pearsall sent me the first specimens found, asking if it was not 

 Naias, and with these specimens a scrap of what I at once saw could 

 only be Hydrilla verticillata Caspary, which was an addition to the 

 flora of the British Isles. Taking the Irish, Scottish, and English 

 specimens of the Naias, they seem to accord with the American 

 plant, and, so far as I have seen, specimens show no approach to the 

 var. microcarpa Nilsson from Lake Ruigsjon in Scania, Sweden. Of 

 this I possess original specimens from Herr Nilsson. This is a smaller 

 plant than ours — 4-10 cm. to 1-50 dm. high, with fruit only 2 — 2-25 mm. 

 long. In Europe Naias occurs in Finland ; Russia, in Lithuania, 

 Olentz, and Borussia ; Germany, in Pomerania, Marchin ! 

 (Pasteiner-See, &c.) ; Sweden, Upland ! (formerly) and Scania ! ; 

 N. America, from Labrador to New England States across to Oregon. 

 This shows what may be expected when our English Lakes are investi- 

 gated as the Scottish ones have been by Mr W. West." — A. Bennett. 



Hydrilla verticillata Gasp. Esthwaite Water, v.-c. 69b, July 

 31, 1914. New to Britain. Grows in slightly coloured water 

 at about 8 feet, and is invisible from the surface. Associated 

 with it are Naias flexilis, Pot. pusillus, Pot. Sturrockii, and 

 Callitriche autumnalis — the first named being dominant. Elodea 

 canadensis, though abundant elsewhere in the lake, is not included in 

 this interesting linear-leaved association. The plant is uniformly 

 pale green in colour, extremely slender and brittle. The branching 

 is mainly below, the long resultant erect shoots being nearly simple. 

 The internodes are | inch to | inch (rarely 1 inch) in length and 

 therefore much more distinct than those of Elodea. The leaves are 

 most often in whorls of 5, but 3's and 4's are frequent, and near the 

 base of the shoots whorls of 3 shorter and broader leaves are common. 

 The leaves are narrowly linear, pellucid, usually just ov^r \ inch long, 

 patent, acute, and minutely serrulate The teeth are few, small, very 

 acute, antrorse, extra marginal, more distant below, and best seen 

 near the apex. I am informed that the leaves are more nearly entire 

 than those of other European specimens of this species at Kew. I 

 was unable to find flowers, but winter buds were prominently shown 

 on specimens gathered later in the season. — W. H. Pearsall. 

 " Hydrilla verticillata, var. gracilis.^'' — A. J. Willmott in lit. " I 

 refer it to var. pomeranica (Reichb.). See B.E.C. Report 1914, p. 

 22."— G. C. Druce. 



Eriocaul on septangular e With. Craigga More, Gal way W., 

 August 14, 1913.— W. C. Barton. 



