LEPIDOPTERID FLOWERS 125 
Many Butterfly Flowers are distinguished by an agreeable and often very 
powerful odour, that not infrequently resembles vanilla, and this strongly attracts 
the special visitors. 
Moth Flowers, as Sprengel long ago stated (‘Entd. Geh.,’ p. 16), are white 
and devoid of nectar-guides (cf. p. 6). They possess, however, an odour that is 
frequently very powerful, and which is perceived from a great distance by the moths 
which visit and pollinate them. Kerner (‘ Nat. Hist. Pl.,’ Eng. Ed. 1, pp. 208, 209), 
for example, narrates that during the daytime he marked a Convolvulus Hawk-moth 
(Sphinx convolvuli) with vermilion, and set it down at a distance of roo metres 
from a honeysuckle plant (Lonicera Caprifolium). ‘When twilight fell the hawk- 
moth began to wave the feelers which serve it as olfactory organs hither and thither 
a few times, then stretched its wings and flew like an arrow through the garden towards 
the honeysuckle.’ When Kerner got there, he found the moth sprinkled with ver- 
milion fluttering in front of the honeysuckle flowers and sucking nectar. It must 
therefore have perceived the odour of the blossoms from a distance of 100 metres. 
The strong aromatic odour of the flowers belonging to this group becomes 
especially noticeable towards evening, while by day it may entirely or almost entirely 
disappear. Moth Flowers open exclusively or chiefly at dusk. The most highly 
specialized flowers of this group are those in which the nectar is hidden so deeply 
2 
Fic. 37. Hawk-moth Flowers. (1) Lilium Martagon Z. (2) Lonicera Periclymenum Z. 
that it can only be rifled by Hawk-moths (Sphingidae), in which the proboscis is 
extremely long. As these Lepidoptera have the habit of sucking nectar as they 
hover before the flower, many Hawk-moth Flowers (e.g. Lonicera Caprifolium and 
Periclymenum, Lilium Martagon) are characterized by anthers which are but loosely 
attached to one point of the filament, so that they readily touch the body of the moth 
as it hovers in front of them (see Fig. 37). 
The stamens of other species of this group of flowers do not exhibit the pecu- 
liarity just described at all, or only to a slight extent, e.g. Platanthera bifolia, Silene 
nutans and inflata, and Convolvulus sepium. 
Although the last-named species is visited during the day by insects, especially 
by bees, its chief pollinators are moths, of which the most important is Sphinx 
convolvuli. According to F. Buchanan White (J. Bot., ii, 1873), Convolvulus 
sepium seldom fruits in England, where the Convolvulus Hawk-moth is uncommon, 
and in Scotland, where this insect does not appear to occur, the plant is very rare. 
