CRASSULACEAE 



425 



Friese (Thuringia) noticed parasitic bees (1. Coelioxys elongata Lep., and 2. 

 Stelis signata Lfr.) and po-cltg. bees (3. Anthidium lituratum Pz., and 4. A. punc- 

 tatum /Jr.). 



997. S. boloniense Loisel. ( = S. sexangulare L.). (Schulz, 'Beitrage,' I, 

 P- 39-) Schulz states that in the yellow flowers of this species the stigmas are 

 perfectly mature when the outer stamens are dehiscing. Automatic self-pollination 

 is quite possible, for the stamens bend towards the stigmas ; but would appear to 

 be seldom resorted to, since numerous insects are attracted by the yellow colour of 

 the blossoms, as well as by the abundant nectar, which is secreted as in S. acre. 



998. S. alpestre Vill. ( = S. repens Schleich.). (Herm. Muller, ' Alpenblumen,' 

 pp. 82-3.) This species is native to the high Alps. Its flowers are protogynous, 

 but the stigmas continue functional till the anthers dehisce, so that automatic self- 

 pollination is possible should insect-visits fail. (Cf. Fig. 141.) 



Visitors. Herm. Muller observed 2 Hymenoptera, a Dipterid, and 2 Lepidoptera. 



999. S. albescens Haw. (=S. rupestre L.) 



Visitors. MacLeod observed 2 bees (Bombus and Andrena) and a butterfly 

 (Lycaena) in the Pyrenees. 



1000. S. annuum L. (Schulz, 'Beitrage,' p. 77.) The flowers of this species 

 are mostly pale-yellow in colour. Schulz states that when they Open the stigmas are 



Fig. 142. Sedum alralum, L. (after Herm. Muller). A. Flower in the first (female) stage. R. Three 

 carpels of the same, seen from without. C. Flower towards the end of the second (male) stage. D. Flower 

 after fading, (x y.) a, anther ; _fi, filament ; , nectary ; ov, ovary; p, petal ; s, sepal ; s/, stigma. 



receptive, remaining so throughout anthesis. The anthers of the outer stamens 

 dehisce as soon as the flower opens, and then those of the inner ones. The stigmas 

 and anthers being close together and at the same level, automatic self-pollination 

 is at first possible, or even inevitable ; but the inner stamens curve outwards towards 

 the end of anthesis, thus favouring cross-pollination. Lindman too found the 

 flowers to be protogynous at first, afterwards becoming homogamous and capable 

 of automatic self-pollination. Kerner says that the outer stamens serve for self- 

 and the inner ones for cross-pollination. He also states that this annual species 

 hybernates by means of rosette-shaped offshoots, should winter set in early and 

 prevent the ripening of fruits. 



Visitors. Schulz observed occasional flies and Ichneumonids at Bozen. 



1001. S. atratum L. (Ricca, Atti Soc. ital. sc. nat., Milano, xiii, 1870, p. 256; 

 Herm. Muller, 'Alpenblumen,' pp. 79-80; Kerner, 'Nat. Hist. PL' Eng. Ed. r, II, 



