204 



Fr. J. Mathiesen. 



colour and become red when the flower has reached the 

 stage of pollination. This is effected either by insects (Le- 

 pidoptera, Hymenoptera and, especially, Diptera), or by 

 self-pollination, in the absence of these. The limb of the 

 corolla also assumes a faint pink colour. This difference in 

 colour between younger and older flowers is presumed to be 

 a signal to the more intelligent insects, that the older flowers 

 have already been cleared of honey by earlier visitors, hence 

 they avoid the red flowers, and the result for the plant is a 

 more intensive utilisation of the visits by insects (H. Müller). 



Fig. 20. Androsaces chamaejasme. 



A and B, flowers seen from above; Л from Herschell Island, В from 



Chabarowa, (^2)- C, flower, transverse section, (Vs). 



Miss A. Eastwood mentions the change of colour in the 

 corolla, so that it must also occur in arctic localities (Alaska). 



Honey is secreted on the cup-shaped surface of the 

 ovary (H. Müller). 



Anatomy. An adventitious root, 0.5 mm in thickness, 

 examined by me, was found to be 3-rayed, but had otherwise 

 the same anatomical structure, as the root of A. septentrionalis. 



The stem of A. chamaejasme, like that of other 

 Androsaces species with a similar mode of growth [A. lactea 

 (Wydler, 1859), A. villosa (Decrock, 1901)], shows a di- 

 stinct difference as regards the structure of the naked long- 

 shoots and the densely-leaved short-shoots. 



As to the first, fig. 21 A illustrates a transverse sec- 

 tion of a stem, which has carried a rosette with few leaves ; 



