184 

 SHORT NOTES. 



PoTAMOGETON DECiPiENs, Nolte, vav. AFFiNis, mihi. — Mr. A. 

 Brotherston, of Kelso, has for some years collected specimens of a 

 Potamogeton from various stations in the River Tweed ; these were 

 at first named " nitens, large form." Notes upon it will be found 

 in Journ. Bot. viii. 289, and in the ' Exchange Club Reports ' for 

 1876, p. 35; 1877, p. 10; and 1880, p. 35; but no definite con- 

 clusion was arrived at as to its proper name. Mr. Brotherston 

 kindly sent me last autumn a fine series of the plant, and after 

 comparing these with others I propose the above name for it. So 

 far as the English herbaria are concerned, we have nothing that 

 matches it ; but the Rev. T. Morong tells me that specimens from 

 Silesia (R. von Uechtritz ) in his herbarium are the same thing ; 

 and Dr. Tiselius (Stockholm) writes me that the late Prof. E. 

 Fries gathered it in the neighbourhood of Upsala. In the Fl. of 

 Silesia it is named " P. decipiens, Nolte ! forte P. perfoliatus x lucens,'" 

 with a critical note on the plant. As to the question of hybridism, 

 this is certainly, as yet, unproved. It is not typical decipiens, 

 Nolte, as the author's t^^pes show in Herb. Brit. Mus. ; and I 

 cannot agree with Dr. Trimen that it approaches P. salicifoHus, 

 Wolf, (except in one or two immaterial points), which has leaves of 

 the texture and structure of i^ralongiis and rufescens rather than of 

 this variety. It is also certainly not P. nitens, Web., which in its 

 extreme iormi^latifolius, Tis. ! 1881, — a name which cannot stand, 

 as Fieber years ago separated a var. latifolius of nitens), through 

 the typical form of Weber to the curvifolius of Hartman, bears no 

 resemblance to this variety of decipiens. It differs from decipiens, 

 as represented by Nolte's type specimens, in the leaves being half- 

 clasping, with a peculiar curvature from the centre of the leaf, the 

 peduncules longer, spikes much shorter, sepals different in shape, 

 and the arrangement of the flowers on the axis of the peduncule, 

 in habit, and in the branching of the stems. — Arthur Bennett. 



Additions to the British Lichen Flora. — The following 

 Lichens have been identified, and, so far as I am aware, they have 

 not hitherto been recorded for Great Britain : — 



Sirusiphon ocellatus (Dillw.), Ktz. — On damp rocks, at the foot 

 of Bowness Knot on the north side, Ennerdale, Cumberland, 1881. 

 Rare. 



Lecanora citrina, Hoffm. — Not in fruit, Great Orme's Head, 

 1881, J. E. Grijfith. 



L. suhradiosa, Nyl., Flora, 1872. — On walls, East Allendale, 

 Northumberland, 1881. Rare. 



L. fjalactina, forma ferrotincta, Njd. — On slaty rocks, Lamplugh, 

 Cumberland, 1881. Dr. Nylander suggested the name given this 

 form, on account of the rusty tincture of the thallus. 



Lecidea enterochlora, Tayl. ; forma tiiberculata, Johnson. — 

 Thallus rimulose or verrucoso-diffi-act ; apothecia more or less 



