1912-13.] BOTANICAL SOCIETY OF EDINBURGH 193 



that its length is relatively to that of the calyx as three to 

 one : along with this goes a marked narrowing of the tube, 

 and the whole corolla in P. Lacei, Hemsley et Watt, is 

 somewhat salver-shaped. In the other species the corolla 

 only slightly exceeds the calyx, and its tube has a curiously 

 transverse ridging on the inside below the anthers — a 

 character that is not shown by the corolla-tube of P. L 

 Hemsley et Watt. This marked divergence in the flower 

 envelope characters might, in association with other features, 

 be regarded as pointing to a natural severance of the 

 Baluchistan plant from those with which I associate it here, 

 were it not that in P. pseudobructeata, Petitmengin — a 

 plant I am sorry to say I have not yet seen — there appears, 

 from the description and from the comments of Petitmengin, 

 who specially notices it. to be a connecting link. It has 

 flower envelopes which are somewhere midway between 

 those marking the Chino-Tibetan forms and those of the 

 Baluchistan plant. The further finds which I anticipate 

 of members of the series in the intervening area will have 

 additional interest on this account. 



The fruit characters in the species in which we know 

 them are uniform. The globose or slightly ovoid capsule 

 is inclosed in the tube of the calyx, barely projecting 

 beyond, and it dehisces by live crustaceous valves right 

 from apex to base. The valves vary in acuteness and 

 width. 



The assemblage of characters here enumerated {rives a 

 distinctiveness to this group of an unmistakable kind. 

 Many of the vegetative characters may be correlated with 

 calcicoly. and this is the habitat assigned to all the species 

 by collectors who have given indications. Alas, how few 

 do so ! I have already referred to the excellent charac- 

 ;tions given by Mr. Forrest in his tickets attached to 

 his herbarium specimens. In respect of this information 

 Mr. Forrest as a collector is unrivalled, as he is also in 

 the marvellously perfect condition and the fullness 

 his specimens. 



As regards distribution, the species of the group are 

 mainly found upon the alps of Yunnan and the borders of 

 Tibet. P. Lacei, Hemsley et Watt, is an outlier. It is a 

 far cry from Yunnan to Baluchistan ; and were the inter- 



