SAXIFRAGEAE 



405 



959. S. adscendens L. The nectar is exposed in this species. Kerner 

 describes the flowers as protogynous. At first only the stigmas are mature, so that 

 cross-pollination may take place ; later on the outer anthers bend over the stigmas, 

 and shed their pollen upon them, so that failing insect-visits automatic self-pollination 

 may be effected. In the third stage of anthesis the stigmas shrivel up, while the 

 inner anthers dehisce and offer their pollen to insect visitors. 



Lindman says that, on the Dovrefjeld, the flowers are homogamous, and 

 effectively autogamous. 



960. S. controversa Sternb. Kerner describes this species as trimonoecious. 



961. S- longifolia Lapeyr. The white blossoms of this species are aggregated 

 into many-flowered inflorescences : the nectar is exposed. MacLeod describes them 

 as protandrous in the Pyrenees, becoming homogamous towards the end of anthesis, 



C. 



$Y& 



Fig. 131. Saxifraga granulata, L. (from nature). A. Flower in the first part of the first (male) 

 stage : several of the outer anthers have dehisced, or are already empty, while the inner ones are 

 still unripe, and the stigmas are immature. B. Flower in the second half of the same stage : all the 

 outer anthers are empty, those of the inner whorl are partly covered with pollen, partly unripe, and 

 the stigmas are still immature. C. Flower in the second (female) stage : all the anthers are empty, 

 and the stigmas are mature, a 1 and a 2 , outer and inner anthers : s, stigma. 



so that automatic self-pollination is ultimately possible. Anthesis apparently lasts 

 for several weeks, the various stages following one another very slowly. 



Visitors. MacLeod observed a few Muscids (Bot. Jaarb. Dodonaea, Ghent, iii, 

 i8gi,p. 425). 



962. S. ajugifolia L. 



Visitors. MacLeod observed 4 species of flies in the Pyrenees. 



963. S. granulata L. (Sprengel, 'Entd. Geh./ pp. 242-4; Herm. Miiller, 

 Weit. Beob.,' I, pp. 296-7; Knuth, 'Bl. u. Insekt. a. d. nordfr. Ins.,' p. 154, 



' Bloemenbiol. Bijdragen.') The white flowers of this species are markedly pro- 

 .androus. Sprengel describes the green nectary as being situated on the upper 

 side of the ovary. The calyx holds the petals so closely together that they form 

 a tube, in the base of which the nectar is sheltered from rain. When the flower 

 opens the anthers are still unripe, and the filaments short. Two of the latter 

 rapidly elongate, and assume an oblique position, in such a way that their anthers, 

 which have meanwhile dehisced, lie immediately above the pistil. When these 

 stamens have shed their pollen, they bend back towards the petals, and two or 



