OBSERVATIONS ON INDIAN PRIMULAS, 



297 



(figs. 71, 72, 73). As the result of a fairly extensive study of Primroses, 

 I have come to put much value on these characters, more in fact than on 

 the shape of the flowers or even of the fruits. Primroses are spring flowers 

 as a rule, and in consequence their attendant insects are comparatively 

 few. The ahsence of a fair assortment of the agents of fertilisation might 

 easily be assumed to originate extreme and direct adaptations ; hence a 

 few thousand feet in altitude, still further lessening the supply of insects, 

 might easily be accepted as producing many so-called Alpine species that 

 have depended for their separate recognition on their possessing a differently 

 shaped or differently coloured flower from that of another plant, with 

 almost identical leaves, seen at lower altitudes. But while it is by no 

 means an uncommon circumstance for an umbellate species to produce 

 solitary flowers (fig. 73, a') — that is, flowers borne on a simple axillary 

 peduncle — the Alpine conditions of capitate species are, as a rule, but 

 dwarfed states and are rarely solitary-flowered, so, conversely, in the 

 luxuriant conditions they never become verticillate. I would next men- 

 tion that the nature of the bracts is most valuable in classification. In 

 the capitate forms there is a bract for each flower, but they are variously 

 assorted in an involucre and are of different sizes. In the umbellate 

 forms the bracts are mostly arranged in a 1 -seriate whorl (fig. 72). So 

 again many Primroses have obovate-spathulate leaves that gradually taper 

 into winged or sheathing bases, but have no true stalks (fig. 69). Others 

 have more or less rotund leaves, borne on pronounced leaf-stalks (fig. 73, 

 d and e). I put considerable value on the shape of the, leaf, when taken 

 in conjunction with the vernation, the pedicels, and the bracts. 



I trust, gentlemen, you are not impatient with me for going into such 

 details, but they have a practical bearing. I am not aware of any hybrid 

 having been made between capitate and pedicellate species, or between 

 typical linear-oblong and rotund-leaved forms. If I be correct, therefore, 

 in that assumption, the science of hybridisation would give (and I believe 

 it always gives) useful hints for the final determination or delineation of 

 doubtful species. In other words, I take it that crosses are as a rule more 

 readily accomplished between allied than remote species. This at least 

 is my apology for furnishing the classification of the Indian Primroses 

 that I now desire to place before you. 



Classification of the Indian Primulas. 



a. leaves revolute in vernation. 



(a) Flowers sessile {capitate). (WJien solitary the capitulate character 

 is presumed to be indicated by the position of the bract outside the calyx.) 



Section 1 : Denticulata (fig. G9). — Leaves thick, usually rugose and 

 glabrous (very rarely puberulous), oblong, spathulate, serrate, and mealy. 

 Inflorescence capitate, the flowers being relatively small and mostly erect, 

 sessile or nearly so, inserted on the top of a swollen peduncle, but in 

 number from one to many. Corolla, tube narrow subcylindrical, lobes 

 bifid. Bracts one to each flower, the outermost gibbous, but they do not 

 form a 1-seriate whorl, nor are they retained in an attitude parallel to 

 each other, but when the flowers are solitary the bracts are usually very 

 large (see P. muscoides). 



