LEPIDOPTERID FLOWERS 



123 



and longer 'humble-bee door,' and a narrower, round ' Lepidoptera door' (Fig. 35). 

 Through the former, Bombus altlcola, mendax, mesomelas and pratorum thrust 

 their proboscis and, sucking in the normal way, effect crossing; through the 

 latter Colias Phocomone and Pieris napi introduce their 

 slender trunk and, also sucking in the normal way, bring 

 about the same result. 



Other Hymenopterid-Lepidopterid Flowers, usually 

 without separate means of access for insects of the two 

 classes, are the following: Gentiana obtusifolia, cam- 

 pestris, nana, involucrata, and tenella; Viola tricolor van 

 alpestris, Scutellaria alpina and galericulata, Oenothera 

 biennis and muricata. 



7. Lepidopterid Flowers (L), 



Fig. 35. Rhinanthus Alecto- 

 rolophits, a Humble-bee Lepi- 

 dopterid Flower, fth, Lepido- 

 ptera door ; hth, Humble-bee 

 door; j/, stigma. 



These are chiefly visited by Lepidoptera, of which 

 the long, slender proboscis is able to reach the nectar, 

 that is concealed in deep and narrow tubes or spurs. 

 They fall into two groups : 



(a) Butterfly Flowers (Lb), which are usually red, e. g. INIelandryum 

 rubrum, Dianthus Carthusianorum ; 



((5) Moth Flowers (Lm), which are white or whitish, e.g. Melandryum 

 album, Lonicera Periclymenum. 



Lepidopterid flowers, according to my statistical summaries (' Bliitenbesucher/ 

 II, p. 8), are eagerly visited by Lepidoptera, though long-tongued bees, and even 

 hover-flies with a proboscis long enough to reach the nectar, are also among 

 their zealous visitors (cf. Fig. 36). The more deeply the nectar is concealed the 

 more exclusively is it secured by Lepidoptera, among which the Hawk-moths 

 (Sphingidae) are the most specialized for the purpose. It follows that 'Hawk-moth 

 Flowers ' are inaccessible to other Lepidoptera with a relatively short proboscis. 

 In less modified flowers the visitors and pollinators are, as already stated, not so 

 exclusively Lepidoptera, but also belong to various other insect groups, so that 

 transitional forms can be recognized : Lychnis Flos-cuculi, for example, is inter- 

 mediate between Bee Flowers and Butterfly Flowers (Lb), while Oenothera biennis 

 is intermediate between Bee Flowers and Moth Flowers (HLm). 



Hermann Miiller ('Alpenblumen,' pp. 509 and 510) came to similar conclusions. 

 Of the thirty-three Lepidopterid flowers which he saw visited by insects in the Alps, 

 eight were visited exclusively by Lepidoptera, i.e. Orchis globosa, Lilium Martagon 

 and bulbiferum, Gymnadenia odoratissima ; Dianthus superbus, sylvestris, atrorubens ; 

 Daphne striata. There were also eight others, apart from Lepidoptera, that were 

 only visited by insects which did not prejudice the interests of the latter in the 

 smallest degree, since they either made vain efforts to reach the nectar, or contented 

 themselves with pollen. The flowers in question were : Gymnadenia conopsea, 

 Nigritella, Viola calcarata, Lychnis Flos-Jovis and rubra, Gentiana bavarica and 

 nivalis, and Paradisea Liliastrum. In the other species it was mostly tiny flower- 



