404 



ANGIOSPERMAE—MONOCOTYLEDONES 



2621. H. hyperborea R. Br. ( = Platanthera hyperborea Lindl). — Warming 

 describes the flowers of this species as possessing a vanilla odour, and Darwin states 

 that they are regularly self-fertilized. 



2622. H. viridis R. Br. (=Peristylus viridis Lindl). (Danvin, op. cit., 43, 63, 

 255 ; Herm. Miiller, ' Alpenblumen,' p. 72.) — 



Visitors. — Probably small moths. 



819. Platanthera Rich. 



2623. P. chlorantha Cust. (=P. montana iJezVy^^.y. ; Habenaria chlorantha 



Bab. ; and H. bifolia R. Br., according to the Index Kewensis). (Darwin, ' Orchids,' 



p. 69; Herm. Miiller, 'Alpenblumen,' p. 72; MacLeod, Bot. Jaarb. Dodonaea, 



Ghent, v, 1893, p. 323; Kirchner, 'Flora v. Stuttgart,' p. 171.) — The almost 



odourless, green flowers of this species are larger than 



those of Habenaria hyperborea, and the spur is 23-43 mm. 



long ; very rarely, however, flowers entirely without a spur 



occur. The caudicles of the pollinia are united by small, 



drum-shaped expansions to the disks, and as these are 



situated more deeply in the entrance to the spur, the 



pollinia attach themselves to the eyes of visitors. 



Visitors. — Darwin observed 2 moths — a Plusia sp., 

 carrying a pollinium on the edge of one eye ; and 

 Mamestra dentina Esp., with a polhnium on one eye. 



820. Ophrys L. 



Partly fly flowers. Frequently automatic self-pol- 

 lination. Inflorescences unilateral in consequence of 

 twisting of the ovaries. 



2624. O. muscifera Huds. (=0. myodes /acq.). 

 (Darwin, op. cit., p. 45 ; Herm. Miiller, ' Weit. Beob.,' I, 

 pp. 285-91 ; Kirchner, op. cit., p. 172.) — The elongated, 

 velvety labellum in this species is blackish-purple in 

 colour, marked with an almost square, glabrous, pale- 

 bluish central patch ; it secretes small drops of nectar 

 down the middle in a longitudinal furrow for a short 

 time immediately after the flower opens ; later on there 

 is merely a thin, shining, damp layer, which disappears 

 immediately. A button-shaped process, with an almost 

 metallic gleam, situated on each side of the base of the 



labellum, serves as a further attraction. It seems, therefore, that the fly flower is 



a deceptive one adapted to the visits of carrion-flies. 



Visitors. — Herm. Miiller observed Sarcophaga ; insect- visits, however, are so 



few, that the flowers generally remain unpollinated. The same observer also saw 



a fossorial wasp (Gorytes mystaceus L.) on a flower, without obtaining anything, 



however, or removing pollinia. 



Fig. 373. Platanthera clilo- 

 rantka, Cust. (after Pfitzer). A. 

 A flower, seen directly from the 

 front. ^/^/, lateral petals; /?K, 

 labellum ; si si. lateral sepals ; 

 sm, upper sepal ; sp, spur. B. 

 A pollinium, seen from the side. 



