Primulaceae. 



209 



The rhizome is closely covered with slightly branched ad- 

 ventitious roots, up to about 2 mm in thickness; both 

 have a bright, brownish colour. The rhizome attains to a 

 considerable length (up to 5 cm) by continuous annual 

 growth, remaining alive for several years; on one rhizome 

 I have counted up to 3 generations of shoots, plainly defined 

 by the remains of the old peduncles. The withered bud- 

 scales are found at the base of the spring rosettes, which 

 consist of long-stalked ovate foliage-leaves 2 — 4 cm long, 

 0.7 — 2 cm broad. About the middle of July the hiber- 

 nation buds are still small. 



The peduncle carries 2 — 3 f^ f\ 



reddish-violet flowers, droop- 

 ing when in full bloom. 



The pollination process 

 in species of Dodecatheon, 

 according to Kerner (Pflan- 

 zenleben II p. 303), is as 

 follows: The pollen-bearing 

 insect, in search of honey, 

 forces the cone-like column 

 of anthers apart with its 

 proboscis, and during this 

 process part of the pollen 



falls out and becomes attached to the visitor. On the next 

 flower visited by the insect, some of this pollen is left on 

 the stigma and cross-fertilization is brought about. Should 

 such fertilization not be effected, by the non-appearance of 

 visiting insects, autogamy will take place. The short filaments 

 become relaxed towards the end of flowering, and cause the 

 anthers to separate somewhat, whereby the space inside the 

 cone of anthers filled with pollen is opened, and the slightest 

 shake causes the mealy pollen to fall on the stigma situated 

 vertically below the anthers, because of the inverted position 



Fig. 23. Dodecatheon frigidum. 



A, inflorescence (slightly reduced). B, an 

 anther seen from the inside ; the cavities of the 

 anther are open. C, dorsal view of an anther, 

 {B and C, V:)- D, the stigma papillae; (obj. 8, 

 ОС 4.) (Herschell Island.) 



ХХХЛЧ1. 



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