SAXIFRAGEAE 



401 



Visitors. — Herm. Miiller observed almost exclusively flies (2 Empids, 7 Muscids, 

 5 Syrphids) ; also an Ichneumonid. Schiner mentions the Syrphid Sphegina clunipes 

 Fall, as a common visitor. 



947. S. stellaris L. (Herm. IMiiller, 'Fertilisation,' p. 244, ' Alpenblumen,' 

 pp. 90-2.) — The flowers of this species are stellate, with half-concealed nectar. 

 Stamens and carpels mature in the same order as in S. rotundifolia, but the times 

 of ripening of the individual stamens overlap to a greater extent. Automatic self- 

 pollination does not usually take place, but perhaps occurs in dull weather or if 

 insect-visits fail. Schulz says that the terminal flower is often female. According 

 to Ekstam, the flowers are protandrous in the Swedish Highlands at Dovre, and 

 also in Nova Zemlia, while on the Ronde and Tronfjall they are almost homogamous. 



Fig. I2Q, Saxifraga stellaris^ L. (after Herm. Miiller). A. A bilaterally symmetrical flower in 

 the middle of the first (male) stage. B. A radially symmetrical flower at the end of the same stage. 

 C. Flower in the second (femalej stage, a-a'', anthers ; y?, filament; w, nectary; ov^ ovary; j, sepal; 

 /, petal ; st, stigma. 



On the Dovrefjeld, on the other hand, according to Lindman, the flowers 

 are markedly protandrous, but on the Tronfjeld, and in Langluplad, they are 

 almost homogamous, and self-pollination is ultimately possible. In Greenland 

 Warming observed homogamy and protogyny as well as protandry (Bot. Tids., 

 Kjobenhavn, xvi, 1888, pp. 10-14). He found ripe fruits on the Sukkestop. In 

 63° N. lat. there occurs a variety, comosa Poir., that propagates by rosettes of leaves, 

 which fall off. These originate from flowers. 



Abromeit also made observations on the variety in Greenland, and noticed 

 properly developed terminal flowers, or else flowers with minute petals (var. crypio- 

 pdala) at the ends of rosette-bearing branches (' Bot. Ergeb. von Drygalski's 

 Gronlandsexped.,' p. 33). The normal flower possesses white, clawed petals, with 

 two yellow spots at the base of the lamina. The anthers vary in colour from white 

 to pale violet and purple ; the pollen is vermilion. 



Ekstam says that in Spitzbergen the variety propagates entirely by rosette-shaped 

 leaf-buds, which easily fall off and take root (' Blutenbiol. Beob. a. Spitzbergen,' 

 p. 12). Andersson and Hesselman state that the process commences at the beginning 

 of August and goes on for a considerable time (' Bidrag till Kanned. om Spetsbergens 

 o. Beeren Eil. Karlvaxtflora,' p. 23). 



DAVIS. II D d 



