188 TRANSACTIONS OF THE [Sess. 



Primulas of the Bullate Section. By Professor 

 Bayley Balfour, F.R.S. (Plates VII.-XII.) 



We are still far from having a satisfactory distribution 

 of the species of Primula into natural sections within the 

 genus, and until further exploration has brought to our 

 knowledge the many species that undoubtedly still await 

 discovery throughout the Himalayas and Western and 

 Central China, we can do little more in the way of 

 systematic grouping of the species than arrange, accord- 

 ing to what appear to be their degrees of likeness, such 

 forms as have become known to us, leaving to the 

 future the discovery of the definite branches of the 

 phyletic tree. 



The section Bullatae which I wish to deal with here was 

 established by Pax on the ground of a general occurrence 

 of leaves with bullate upper surface in the species which he 

 included in it, but the assemblage he created is only partly 

 natural. Five species make it up, namely : Primula 

 Davidii, Franchet ; P. ovalifolia, Franchet ; P. bullata, 

 Franchet; P. bracteata, Franchet; P. Henrici, Bureau et 

 Franchet — all of them Chinese. 



Showing you, as I now do, specimens of these species 

 (except P. Henrici, Bureau et Franchet — a plant which I 

 have not yet seen), you will recognise that there is a 

 marked difference in their outward appearance. There 

 is, no doubt, a certain amount of resemblance in the 

 bullation of the leaves in all of them ; but P. Davidii, 

 Franchet, and P. ovalifolia, Franchet, are herbaceous 

 species very different in habit from P. bullata, Franchet, 

 and P. bracteata, Franchet, which are woody and perennial 

 evergreens. 



P. Davidii, Franchet, and P. ovalifolia, Franchet, have 

 indeed no right to be here at all, and in their fruit character 

 they resemble the Indian species P. obtusifolia, Boyle, and 

 others in which the summit of the capsule breaks irregularly, 

 leaving a large pore. This character has sectional value in 

 the genus. 



In any case, the consideration of P. Davidii, Franchet, 

 and P. ovalifolia, Franchet, in connection with these woody 





