434 Fr. J. Mathiesen. 



the now dead leaves x and y are from the leaf-rosette formed 

 the year before the main shoot flowered; from the axil of one 

 of the uppermost bud-scales, an innovation shoot E has also 

 been developed, and is expanding its first two fohage-leaves. 



Here, consequently, the vegetative-stage has lasted 3 

 years, and this appears to be the rule in individuals of this 

 type; in the tuft-forming type in which, in dried material, 

 this question is far more difficult to decide, it appears to me 

 that the vegetative stage can be restricted to two years. 



It still remains to be noted that, although the majority 

 of the individuals which result from isolated innovation 

 shoots, had elongated internodes inserted between the ro- 

 settes, yet only rarely were they as long as is shown in Fig. 

 26, 2; the phenomenon is probably due to^the endeavour of 

 the plant to keep its terminal bud in a certain position rela- 

 tive to the surface of the substratum. In Fig. 26, 1 adventi- 

 tious roots are developed only at the base of the shoot, but 

 these may also be developed below the other rosettes, often 

 in great numbers. They are 1 — 2 mm thick. I never found 

 haustoria on such adventitious roots, but they occurred on 

 the root-branches in the specimen from Herschell Island, 

 mentioned above. 



From Nova Zembla piants were to hånd of which the 

 peduncle was only 5 cm high during flowering; in specimens 

 from Chabarowa it was 17 cm, and in one from Churchill, 

 even 25 cm high ; after flowering an elongation of the axis 

 of the inflorescence takes place. 



Fig. 26, 2 shows a flower seen from the side. The posi- 

 tion of the stigma should be noted, and the two pointed 

 lobes in which the front part of the helmet terminates, and 

 the ridge, with the veins which proceed from it into the 

 helmet, also the slightly warty revolute portion of the edge 

 of the upper lip, and the two convexities on the lower hp; 



