192 ANGIOSPERMAE—DICOTYLEDONES 



476. S. crassifolia Ehrh. — In Denmark, Warming observed gynodioeciously 

 distributed female flowers in addition to the markedly protandrous hermaphrodite 

 ones. Wamstorf describes the flowers at Ruppin as being also protandrous. 



477. S. longipes Goldie. — Warming states that the hermaphrodite flowers of 

 this species are protandrous or homogamous in Greenland, while self-pollination 

 appears to be prevented by the distance between anthers and stigmas. The female 

 flowers are gynodioeciously distributed, as also in Spitzbergen, where, however, they 

 are remarkably small. 



Ekstam describes the flowers in Nova Zemlia as odourless, protogynous- 

 homogamous, and 8-1 2 mm. in diameter. In Spitzbergen and Greenland, according 

 to Warming, the hermaphrodite flowers are protandrous-homogamous, or homogamous, 

 and there are also purely female ones. 



Andersson and Hesselman state {' Bidrag till Kanned. om Spetsbergens o. Beeren 

 Eil. Karlvaxtflora,' p. 56) that this species flowers in Spitzbergen from the middle 

 of July till the end of August, and ripens its fruits. Ekstam (' Bliitenbiol. Beob. a. 

 Spitzbergen,' pp. 25-6) gives the diameter of the flowers of the variety humilis Fenzl 

 as 8-12 mm., and he noticed some instances of apetaly. The sexual organs mature 

 simultaneously after the flowers have opened, and autogamy is rendered possible 

 by bending of the stamens towards the stigmas. The floral receptacle obviously 

 secretes nectar between the bases of the stamens. 



In Greenland this extremely variable plant is so abundant that it serves as food 

 for reindeer (Abromeit, 'Bot. Ergeb. v. Drygalski's Gronlandsexped.,' pp. 21-2). 



Visitors. — On four diff'erent days Ekstam noticed several small Diptera in 

 Spitzbergen, and he observed a medium-sized fly in Nova Zemlia. 



478. S. humifusa Rottb. — In Greenland, according to Warming, the 

 hermaphrodite flowers of this species are usually protandrous, rarely protogynous, 

 but in later stages they are always homogamous. The female flowers are distributed 

 in Spitzbergen like those of the last species. Warming saw no fruits, and there 

 is probably a large amount of vegetative propagation by means of buds. 



For Nova Zemlia Ekstam gives the diameter of the protogynous-homogamous 

 flowers as 10-15 mm. Self-pollination is possible. There is sometimes a tolerably 

 strong odour of honey, associated with the secretion of a considerable quantity 

 of nectar. 



According to Andersson and Hesselman (op. cit., p. 56), this species flowers 

 in Spitzbergen from the middle of July to the end of August, and ripens fruits. 

 Ekstam (op. cit., p. 26) gives the diameter of the flowers as 6-8 mm. ; in Greenland 

 it is 8-10 mm., according to Abromeit (op. cit., p. 20). Ekstam observed slight 

 protandry. 



Visitors. — Ekstam observed a small fly in Nova Zemlia. 



479. S. borealis Bigel. — Lindman states that the flowers of this species are 

 homogamous on the Dovrefjeld. Towards the end of anthesis the anthers of the 

 longer stamens come into contact with the stigmas, and self-pollinate them. In 

 Greenland, according to Warming, the flowers are apetalous, homogamous, and 

 automatically self-pollinated. Gynodioecism has also been observed. 



