402 ANGIOSPERMAE— DICOTYLEDON ES 



Visitors. — Herm. Miiller observed flies, almost exclusively (a Dolichopodid, 

 an Empid, 8 Muscids, 2 Syrphids); also occasional beetles, Lepidoptera, and 

 Hymenoptera. In Dumfriesshire, an Empid, 3 Muscids, and 3 Syrphids were 

 recorded (Scott-Elliot, 'Flora of Dumfriesshire,' p. 72). 



948. S. aspera DC. (Herm. Muiler, 'Fertilisation,' p. 244, ' Alpenblumen,' 

 pp. 92-3.) — The blossoms of this species secrete exposed nectar, and belong to the 

 class of fly flowers. As Engler observed, they are markedly protandrous. Auto- 

 matic self-pollination is as a rule excluded. 



Visitors. — Herm. Miiller noticed 2 Muscids ; and Loew (Pontresina) saw a 

 Muscid. 



949. S. bryoides L. (=S. aspera L.\ (Herm. Muiler, 'Fertilisation,' 

 p. 244, ' Alpenblumen,' pp. 93-4.) — Engler was the first to observe protandry in 

 this species. The flower mechanism completely agrees with that of S. aspera. 

 Kerner states that anthesis lasts for eight days. 



Visitors. — Herm. Miiller chiefly observed flies (an Empid, 6 Muscids, 2 Syr- 

 phids) ; also occasional beetles and Ichneumonids. 



950. S. cuneifolia L. (Kirchner, ' Beitrage,' pp. 31-2.) — The flowers of this 

 species secrete exposed nectar. Delpino was the first to call attention to their 

 marked protandry. Kirchner says that the flower mechanism, as observed at Zermatt, 

 comes nearest to that of S. stellaris. Self-pollination is excluded by protandry : 

 it is only when all the anthers have shriveUed and dropped off that the styles 

 separate and expose the stigmas. 



Visitors. — Kirchner observed 2 species of flies. 



951. S. hieracifolia Waldst. et Kit. — The nectar is half-concealed in this 

 species. Kerner, whose observations were made in the Tyrol, noticed that the 

 peduncle bends downwards towards the end of anthesis, so that the stigmas are 

 brought into the line of fall of the pollen, automatic self-pollination resulting. 

 Warming found that self-pollination can also easily take place in Greenland, where 

 the flowers remain more or less closed (Bot. Tids., Kjobenhavn, xvi, 1888, pp. 16-22). 

 Ekstam says that in Nova Zemlia the odourless, inconspicuous, greenish-yellow 

 flowers are markedly protandrous, and 5-10 mm. in diameter. 



Andersson and Hesselman state that the species flowers in Spitzbergen from 

 the beginning of July till the beginning of August (' Bidrag till Kanned. om Spets- 

 bergens o. Beeren Eil. Karlvaxtflora,' pp. 21-2). Fruits are regularly set, and are 

 in some cases fully ripe by the end of August. Ekstam, for Spitzbergen, describes 

 the flowers as 5-10 mm. in diameter, odourless, and protogynous to homogamous : 

 the stigmatic surfaces separate and assume a glistening appearance before the anthers 

 are completely ripe (' Blutenbiol. Beob. a. Spitzbergen,' pp. lo-ii). 



Visitors. — Ekstam noticed a medium-sized fly in Spitzbergen. 



952. S. Seguieri Spreng. (Herm. Muiler, 'Fertilisation,' p. 244, 'Alpen- 

 blumen,' pp. 106-7.) — This species secretes exposed nectar, and its flower mechanism 

 is adapted to the visits of flies. Unlike most others of the genus it exhibits marked 

 protogyny, and the stigmas persist only for a short time. Self-pollination is excluded, 

 for the outer anthers only begin to dehisce after the stigmas have shrivelled up. 



Visitors. — These are flies. 



