332 TRANSACTIONS OF THE [Sbss. lxxix. 



which we owe to Forrest. Of the obconica type, it wants 

 the irritant property of P. obconica, Hance. In cultivation 

 it forms neat dense tufts of dark green leaves, from amongst 

 which the well-balanced scapes ascend, bearing commonly 

 two tiers of flowers which are typically snow-white. It is 

 not quite hardy about Edinburgh, but I believe it thrives 

 out-of-doors in South England. In greenhouse work it 

 should better P. obconica, Hance, and rival perhaps 

 P. sinensis, Sabine, and P. malacoides, Franch. Grown 

 planted out in a frame it flowers throughout the whole 

 year. In my belief it is a coming horticultural plant. It 

 shows some variation in tint of flower ; these are sometimes 

 a pale violet. 



A comparison of Plates XXI (P. obconica, Hance), XXVI 

 (P. Listeri, King), XLVII (P. sinolisteri, Balf. fil.), ought, 

 I think, to satisfy anyone of the justness of the claim of 

 P. sinolisteri, Balf. fil., to its distinctive name as a 

 microform intermediate to the other two plants which have 

 been given specific rank. It is, however, only a phase of 

 physiognomic development in relation to environment, and, 

 as I am about to show, grades on the one side into less 

 xeromorphous, on the other into more xeromorphous forms. 



Of the former, I show in Plate XLVIII an example. 

 This is Forrest's No. 1815, referred to above. The im- 

 pression given one is of a plant of a moister and shadier 

 habitat such as the record asserts. The rhizome is less 

 rigid and developed, the leaves are larger and more 

 membranous, they have a more oval form, and the lobing 

 is but slightly indicated. The scapes are longer, more 

 erect, and the flowers larger, and some of them have very 

 long corolla-tubes. The calyx has not the prominent 

 triangular segmentation — the lobes are broader and more 

 rounded with a mucro. The whole plant is pubescent, and 

 whilst the older leaves are nearly glabrous, as in P. sinolisteri. 

 Balf. fil., the younger ones are hirsute, and there is a 

 tendency to formation of some long hairs at the base of the 

 umbel and of the calyces. 



As an illustration of passage to more xeromorphous 

 forms, I give on Plate XLIX a representation of a plant 

 collected about Tseku by Pere Monbeig (No. 178), without 

 definite statement of habitat. The aspect of the plant 



