30G TFIE JOURNAL OF BOTANY 



The late J. A. Talk's collection of Diatoms, comprising 2665 

 slides, from the Committee of Middlesex Hospital. 



(2) By Purchase. 

 The following are the more important additions : The Botani- 

 cal Exchange Cluh, 419 British Flowering plants ; U. Faurie, 

 1800 Formosa plants ; E. A. Diimmer, 800 plants from Uganda 

 and British East Africa ; and Miss A. Pegler, 50 Fungi from 

 Kentani, South Africa. Continuations of published sets of Euro- 

 pean plants — from H. Dahlstedt, 55 specimens ; H. Sudre, 100 

 specimens ; and of North American Algae by Collins, Holden and 

 Setchell, 100 specimens. 



(3) By Exchange of Duplicates. 

 The Eegius Keeper, Eoyal Botanic Gardens, Edinburgh, 2401 

 plants from China, Tiliet and India ; Director, South African 

 Museum, Cape Town, 100 Basutoland plants ; Director, National 

 Herbarium, Sydney, 101 Australian plants ; Curator, National 

 Museum, Melbourne, 28 Australian plants ; Botanist, Bureau of 

 Science, Manila, 1643 Philippine plants ; Director, Museu Goeldi, 

 Para, Brazil, 94 Brazilian plants ; California Academy of Sciences, 

 North American plants. 



SHOBT NOTES. 



PoTAMOQETON ALPiNus Balb. X LUCENS L. — Mr. Green of 

 Swanage has sent me specimens from Bindon Mill-dam near Wool, 

 Dorset, and from the river Frome above Wareham, which can 

 only be referred to the above hybrid. The finder remarks they 

 both grow with 'perfolialkis L., but the leaf-bases will not allow of 

 that species being one of the parents. I have nothing like these 

 specimens from England before. But we are faced with a diffi- 

 culty. Ascherson & Graebner, in the second edition of their 

 Syn. Mitteleurop. Flora (Potamogeton, p. 501 (1913)), doubtfully 

 refer P. salicifolius Wolfg. to this hybrid : in this Journal for 

 1908 (p. 251) I expressed the same opinion, and Mr. Fryer in his 

 MSS. seems to have come to a similar conclusion. But the leaf- 

 bases in Wolfgang's own specimens, and also in Besser's, are 

 semi-clas:ping, thus indicating that some other species, such as 

 IjerfoliaUis or pircelongtis, has to do with it. At present the matter 

 may rest here, though I am coming somewhat to Dr. Hagstrom's 

 view, that here we have a series of hybrids that eventually must 

 come under P. decijnens Nolte as an aggregate ; indeed, I put 

 salicifolius under deciinens in the last edition of the London 

 Catalogue. Omitting discussion as to this, the specimens from 

 Mr. Green are alpimts x lucens. I have two other interesting 

 forms of the genus under consideration on which I hope to report 

 later. — A. Bennett. 



SiEGLiNGiA (Triodia) decumbens IN Marshy Ground. — The 

 habitat of this grass given in most of the British ' floras ' is such 



