471 



function, on the whole the plant is smaller and weaker than 

 the two other species (Fig. 14,^). The main characters of its 

 shoot-structure have already been mentioned under F. vulgaris^ 

 it only remains to mention a circumstance pertaining to its 

 manner of growth, caused by the more or less rapid growth 

 of the Sphagnum. As the plant is always 

 struggling with this factor, it is compelled to 

 develop shoots with more elongated iinter- 

 nodes than is P. vulgaris., which grows on 

 a more solid substratum. 



In spring the plant grows with elongated 

 internodes, until it gets above the Sphagnum 

 and reaches the light, when it develops its 

 rosette. The tension in the leaves of this 

 species being undoubtedly very weak, the 

 plant must be forced upwards during the 

 summer almost exclusively by the Sphagnum 

 pressing on its stem and leaves, until the 

 the winter-bud develops and the foliage-leaves 

 decay totally ; then the Sphagnum grows forth 

 and covers the plant for the winter. The 

 manner of growth is here quite similar to 

 what is known from Drosera (cf. Th. JNitschke : 

 Wachsthumsverhältnissen d. rundblättrigen 

 Sonnenthaues. Bot. Zeit, 1860, p. 57). Only 

 when the plant does not at first reach above 

 the Sphagnum during its growth by elongated 

 internodes is the case then somewhat different (Fig. 13). The 

 plant will then develop flowers without having formed a spring- 

 rosette, and the rejuvenating shoot will develop with elon- 

 gated internodes, instead of forming a winter-bud at once. 

 Later on, when the growth of the Sphagnum diminishes, the 

 rejuvenating shoot develops a winter-bud at its apex, at a 

 proper distance from the surface of the Sphagnum. By this 



Fig. 13. Pingui- 

 cula villosa. 



A plant, which in 

 spring did not reach 

 above the Sphagnum, 

 and therefore has 

 not developed its 

 spring-rosette; the 

 rejuvenating shoot 

 has formed elongated 

 internodes instead of 

 forminga winter-bud. 

 Not before the shoot 

 reaches to a suit- 

 able depth below 

 the .Spliagnum-sur- 

 face, will the winter- 

 bud develop. The 

 plant belongs to 

 those which are 

 unfitted for the 

 struggle for exist- 

 ence. Luleå Lapp- 

 mark, QuickjocK, 

 July. About IVa 

 nat. size (F. H.) 



