LIU ACE AE 467 



'D. Septaldrusen '; Kirchner, 'Flora v. Stuttgart,' p. 71.) — The flowers of this species 

 are adapted for pollination by bees. The vertically pendulous flower-bells are 

 8-10 mm. long. They secrete abundant nectar at their base. Bees searching for 

 this cling to the lower side of the flower, and touch the introrse anthers with one side 

 of their bodies, and with the other the stigma, which matures simultaneously, and 

 is situated at the same level as the anthers, thus effecting cross-pollination. Nectar- 

 sucking lepidoptera do not necessarily touch both organs with their thin proboscis. 

 Should bee-visitors fail, automatic self-pollination takes place in consequence of the 

 proximity of anthers and stigma. 



Visitors. — Herm. Muller (Alps) observed 2 humble-bees and 2 Lepidoptera. 

 Schulz noticed numerous Hymenoptera and small Lepidoptera : also perforated 

 flowers. 



2806. P. officinale All. {— Convallaria Polygonatum Z.). (Sprengel, ' Entd. 

 Geh.,' p. 198; Herm. Muller, op. cit., pp. 53-4; Grassmann, op. cit. ; Almqvist, 

 Bot. Centralbl., Cassel, xxxviii, 1889, p. 663 ; Kirchner, op. cit., p. 70.) — The 

 flowers of this species are adapted for pollination by humble-bees. They possess 

 an odour of bitter almonds, and conceal the nectar ' in the base of the perianth bell 

 (14-17 mm. long), so that it is only accessible to the longest- tongued bees. The 

 flower entrance is almost filled up by the stigma. As the anthers are situated about 

 3 mm. above the latter, it is touched by humble-bee visitors before the pollen, 

 crossing being thus brought about. Should humble-bee visits fail, automatic self- 

 pollination is eff'ected by fall of pollen. Almqvist found no free nectar in flowers 

 examined by him at Stockholm, but the walls of the ovary and perianth contained 

 sweet juice, which could only be extracted by boring '. 



In the Alps the perianth tube is often perforated, and the nectar stolen, by 

 Bombus mastrucatus. The hole made by this humble-bee is then used by other 

 insects also to steal nectar. I have never observed perforation in flowers in North 

 Germany. 



Visitors.— Loew (Berlin Botanic Garden) observed the humble-bee Bombus 

 lapidarius Z. 5, skg. 



2807. P. latifolium Desf. (= Convallaria latifolia /acq.). (K. F. Jordan, 

 ' D. Stellung d. Honigbehalter.') — In this species the entrance to the flower is 

 situated between the introrse anthers and the stigma, so that suitable visitors must 

 chiefly eff^ect crossing. 



2808. P. multifiorum All. ( = Convallaria multiflora Z.). (Herm. Muller, 

 ' Fertlsn.,' p. 550, ' Weit. Beob.,' I, p. 283 ; MacLeod, Bot. Jaarb. Dodonaea, Ghent, 

 V, 1893, pp. 311-13 ; Grassmann, ' D. Septaldrusen ' ; Kirchner, ' Flora v. Stuttgart,' 

 p. 71 ; Almqvist, Bot. Centralbl., Cassel, xxxviii, 1889, p. 663 ; Warnstorf, Verh. 

 bot. Ver., Berlin, xxxviii, 1896; Knuth, Bloemenbiol. Bijdragen.') — The flowers of 

 this species are adapted for pollination by humble-bees. The perianth tube is 

 11-18 mm. long, and its base, which secretes a little nectar, is only accessible to 

 long-tongued bees, especially as the entrance to the flower is closed by the stigma 

 and the anthers closely surrounding it, and the filaments are beset with hairs. 



' Cf. the foot-note on Lencojum aestivum L. 

 H h 2 



