ORCHIDEAE 



413 



2639. E. atrorubens Schult. (= E. rubiginosa Crantz). (Ridley, J. Linn. 

 Soc. Bot., London, xxiv, 1888; Knuth, ' Bliitenbiol. Beitrage.') The flowers of 

 this species are dark purple-red in colour, and possess a vanilla-odour with an 

 accessory fragrance of pinks. Like those of the two preceding species, they possess 

 a cap over the rostellum which can easily be removed by a light pressure from below, 

 as I found from numerous examples on the Dunes of Usedom. At the time (in 1883), 

 however, I made no further notes ; I also observed no visitors then. Ridley states 

 that the plant is autogamous, pollen-tubes growing directly from the pollinia into 

 the stigma. 



827. Serapias L. 



2640. S. longipetala Pollini. (Delpino, ' Applicaz. d. teor. Darwin.') 

 Visitors. Delpino observed bees in Liguria. 



2641. S. occultata J. Gay. (Nicotra, Malpighia, Genova, i, 1887, pp. 460-3.) 

 Nicotra says that this is autogamous, but heterogamy is not excluded. 



2642. S. Lingua L. In this species autogamy is rendered very difficult by 

 the position of the pollinia, as the falling pollen cannot reach the stigma. Both 

 this species and the previous one resemble Epipactis to some extent in their flower 

 mechanism. 



828. Listera R. Br. 



Nectar exposed. 



2643. L. ovata R. Br. (Sprengel, 'Entd. Geh.,' pp. 406-11 ; Darwin, op. cit., 

 p. 115 ; Herm. Muller, 'Fertlsn.,' p. 295; MacLeod, Bot. Jaarb. Dodonaea, Ghent, 

 iii, 1891, pp. 309-10, v, 1893, pp. 326-8; Kirchner, 'Flora v. Stuttgart,' p. 178.) 



Fig. 382. Listera ovata, R.Br, (after Henn. Mailer), (i) Part of a virgin flower, seen from the side, 

 (a) Flower from the front, after the pollinia have been removed from the anther and the foliate rostellum 

 has bent over and partly covered the stigma (on half the scale of (i) ). (3) The pollinia attached to 

 a needle (x 20). (4) A specimen of Grammoptera laevis with numerous pollinia attached to the front of 

 its head, a, anther ; k, viscid matter ; , nectar-groove ; ov, ovary ; pp, lateral petals ; /', labellum ; po, 

 pollinia ; r, rostellum ; j*, sepals ; 4/, stigmju 



This species bears ichneumon-fly flowers {cf. Vol. I, p. 121). They are inconspicuous 

 and greenish-yellow in colour, possessing a long, nectar-secreting groove in the 



