July, 191 1. The IHsh Nahiralist. 117 



THE BRITISH UTRICULARIAE. 



BY G. CLARIDGE DRUCE, M.A., F.L.S. 

 (Hon. Sec. Botanical Exchange Club of the British Isles). 



In a recent number of the Irish Naturalist I drew attention 

 to my discovery of two species of Utricularia new to 

 Ireland. It may be well to give some description of these 

 and their allies, since doubtless if attention is paid to this 

 group a further extension of the range is sure to be made. 

 The following account is taken from the pages of the Report 

 of the Botanical Exchange Club of the British Isles for 

 1910. Might I say that the Club would be glad to 

 welcome Irish field botanists as members, and I should 

 be glad to send particulars ? 



UTRICULARIA. 



This genus has been recently closely studied by Dr. Hugo 

 Gliick, who in his most interesting account of U. ochroleuca 

 which appeared in the Berichte Deutsch. Botan. GeseUschaft, 

 149-156, for 1902, gave some additional characters 

 by which that species may be distinguished from those 

 previously known, and which enable the plant to be 

 recognised in the barren state. Another very important 

 contribution is that of Fr. Meister (" Memoires de I'Herbier 

 Boissier," n. 12, 1900). From these, and from verbal 

 statements made to me by Dr. Gliick, the following brief 

 description of the British forms has been drawn up, in the 

 hope that it may induce members to study more closely 

 this interesting genus : — 



Clavis. 



A. Submerged floating plants with all shoots of similar 



form. Leaves provided with numerous bladders 

 and divided into numerous hair -shaped terminal 

 segments, the leaf-tips toothed on margin. 

 = 1. U. vulgaris. 2. U. major. 



B. Shoots differentiated into two forms : (i) green 



assimilating shoots which float in water, and 

 (2) colourless shoots which are usually sub- 

 terranean. Leaves divided into 7-20 segments. 



