196 



Fr. J. Mathiesen. 



in Flora Danica and by Blytt. These secondary axes have 

 often some foliage-leaves developed at their base. 



Like other winter annual plants, A. septentrionalis is, 

 according to Brundin, sometimes found flowering in the 

 same year as it germinated. 



The calyx is campanulate with 5 protruding ridges at its 

 base, and its lobes reach somewhat above the corolla-tube. 

 The diameter of the limb was found to be 6 mm on spe- 

 cimens from Öland, 3 — 5 mm on those from the Arctic ; the 

 limb and tube are white. In the throat of the corolla 



there are 5 projec- 

 tions, alternating 

 with the corolla- 

 lobes; they are sac- 

 like expansions of 

 the throat (fig. lö, 

 D, shows part of 

 the corolla seen 

 from the outside). 

 The centre of each 

 projection is some- 

 what depressed (fig. 

 15, A and E). H. 

 Müller remarks, 

 concerning these 

 throat-projections in Androsaces species, that they are yel- 

 low and often very conspicuous, and for this reason he 

 thinks they are of importance as nectar contrivances; they 

 are also useful in narrowing the throat, thus preventing 

 drops of water from finding their way into the corolla tube, 

 and moistening the reproductive organs. The uppermost flat 

 part of the ovary functions as a nectary, and, according to 

 the above author, a drop of honey is here secreted on dry 

 and warm days. 



Fig. 15. Androsaces septentrionalis. 



A, longitudinal section of flower-bud, ( 6 \). R, a recently 

 opened flower, ( 5 /i)- C, a young inflorescence, developed 

 from a bud in one of the uppermost leaf-axils of the rosette, 

 ( 10 /i). D, part of the corolla, seen from the outside; the 

 limb is bent somewhat upwards, to show the throat-projec- 

 tions. E, the corolla, seen from above, (*/i). (Öland.) 



