PRIMULACEAE 



77 



548. Dodecatheon L. 



Undoubtedly pollen flowers with pollen guides. Kerner states that the same 

 kind of autogamy takes place as in Soldanella (' Nat. Hist. PI.,' Eng. Ed. i, II, p. 333. 

 Vide infra). 



1834. D. Meadia L. (=D. frigidum Cham, et Schlecht., and D. integrifolium 

 Michx.). (Loew, ' Bliitenbiol. Beitrage,' I, pp. 17-19.) The flower mechanism of 

 this North American species resembles that of Cyclamen {cf. p. 79). As the flowers 

 wither they become erect and the anthers separate so that pollen can fall upon the 

 stigma, allogamy being thus replaced by autogamy. 



K. Brandegee (Zoe, San Diego (Cal.), i, 1890, pp. 17-20) says that D. JefTreyi 

 Moore, described by Loew (op. cit., p. 463), is a variety of this species. In D. frigidum 

 Cham, et Schlecht. the filaments are so short that they are completely enclosed in the 

 throat of the corolla, from which they project for about 3 mm. in the main type. 

 This difference results in an important modification in the flower mechanism, for in 

 the former case visitors cannot cling to the staminal cone. 



Visitors. Loew saw a small bee (Andrena fulva Schr.) alight on the staminal 

 cone and fly away again after a short lime without obtaining any booty. 



549. Soldanella L. 



Bee-flowers, usually homogamous, rarely protogynous, sometimes with concealed 

 nectar (S. pusilla Baumg., var. inclinata). This is secreted by a ring below the ovary, 

 and stored in the base of the 

 corolla-tube. 



1835. S. alpina L. 

 (Kerner, ' Schutzmittel d. Bl.,' 

 p. 232, 'Nat. Hist. PI.,' Eng. 

 Ed. I, II, p. 368; Ricca, 

 Atti Soc. ital. sc. nat., Milano, 

 xiv, 187 1 ; Herm. Miiller, 

 ' Alpenblumen,' pp. 369-71 ; 

 Schulz, 'Beitrage,' II, pp. 

 149-50.) This species bears 

 bee - flowers. The stigma 

 projects a little from the 

 violet corolla, so that it is 

 first touched by humble-bee 

 visitors, which consequently 

 effect crossing. Miiller de- 

 scribes the flowers as homo- 

 gamous, Ricca and Kerner 

 as protogynous. Should in- 

 sect-visits fail, "Miiller says 

 that automatic self-pollination may be effected by the fall of pollen in the vertical 

 flowers, while Kerner states that it is brought about when the corolla drops off, 

 for the stigma is then drawn through the anthers. i^Cf. Fig. 247.) 



Fig. 247. Soldanella alpina, L. (after Herm. Muller). A. Pisti! 

 and half the calyx, seen from the side (x 3J). S. Partly dissected 

 flower ( X 3J). C. Flower cut through immediately below the nectar- 

 covers (as indicated hy ab m B), seen from below (X 7). co, corolla; 

 _/?, filaments ; gr, style ; , nectary ; s, sepal ; sd, nectar-cover ; sk, 

 nectar. 



