238 



Eue Warming. 



nodes. The primary root remains throughout the whole life 

 of the plant, and can become very long. Kruuse records 

 the length as being 2 m, and Seignette almost 3 m. 



The shoots may most properly be called long shoots, and 

 have close-set leaf-pairs, which do not cross each other at 

 right angles, but grow in such a manner that, for instance, 

 the 1st and the 4th leaf-pair stand perpendicularly above 

 each other. Only a few (usually 4 — 5) fresh leaf-pairs occur 



simultaneously on each 

 shoot, and these appar- 

 ently form a small ro- 

 sette at the end of the 

 stem which is usually 

 closely covered with old 

 leaves and fragments of 

 leaves (Fig. 3). The fresh 

 leaves are immediately 

 succeeded by the soli- 

 tary, terminal flower 

 (Fig. 3, A). 



From the base of 

 the tap-root, leaf-shoots 

 proceed in all directions, 



Fig. 3. Silène acaulis. 

 A, A branch (Norway). B, The apex of 

 a branch seen from above; the leaf-pairs, 

 following each other in succession, are 

 indicated by figures, and are, moreover, 

 shaded in various ways. In the centre 

 are seen two fresh, young foliage-leaves, 

 not yet unfolded (Iceland; H. Jonsson, 

 26.3.1894). C, A branch from northern w hich shoots are more 

 Sweden. (E.W.) 



or less branched, and 



are almost equal in height and are, moreover, almost 



always densely crowded, so that a flattened, semi-globular 



cushion is produced. Schröter (pp. 582 and 583) calls this 



form "Flachpolster." The branching of the shoots in the 



interior of the cushion is well-illustrated in Mrs. Thekla 



Resvoll's Fig. 36, p. 144; a compact tuft is shown "opened" 



and the branches are spread out. There are scarcely any of 



the Arctic Caryophyllaceae which are so typically pulvinate 



