Scrophulariaceae. 409 



that, in which they expand; the same is the case with the 

 buds for the flowers. 



As already mentioned, the portion of the shoot devel- 

 oped during the first year of growth, may either have elong- 

 ated internodes and be runner-like, or — as e. g. figured by 

 Kerner on p. 129 (1. c.) — it may have quite short inter- 

 nodes with close-set scale-leaves; the first 2 — 3 internodes 

 of the stem are, however, generally somewhat longer than 

 those following; and here the scale-leaves are smaller. If by 

 means of the latter form of shoots the ramification should 

 be continued through several shoot-generations, the indivi- 

 dual becomes gradually cæspitose in habit. A tuft of this 

 kind collected by M. Porsild in West Greenland ("heathy 

 slopes") had about 50 older and withered shoots, and some 

 20 fresh ones — both vegetative and flowering. The indivi- 

 dual had sometimes formed quite short runners, adventitious 

 roots were scantily developed, and the entire system was 

 borne by a single root (whether main root or adventitious 

 root was not clear) about 5 mm thick. 



The adventitious roots spring — often abundantly — 

 from the nodes. 



The rhizome, probably as a rule, dies away rather quickly 

 from behind; however, in a specimen from East Greenland 

 with cæspitose habit, a part of it had attained a thickness 

 of fully 5 mm, and the whole system was evidently old. 



The plants are densely covered with hairs especially at 

 the top ; hairs (non-glandular) also occur on the subterranean 

 portions of the shoots, Kerner ascribes importance to these 

 hairs as organs of absorption; according to Heinricher, 

 however, there is no reason to assume that they have such a 

 function. 



The Flower-biology has been dealt with by H.Müller, 

 E. Warming, Lindman, Kerner and others. The accompa- 



