308 The Romance of Wild Flowers 
Lady’s-tresses (Spiranthes autuwmnalis) has some- 
what similar flowers, but white and fragrant, the lip 
channelled at its base, and the tip undivided. Its 
colour and fragrance appeal to a higher group of 
insects, and its fertilisation is undertaken by humble- 
bees in spite of the small size—one-sixth of an inch— 
of its flowers. 
The Helleborines, formerly included in one genus, 
are now divided into the genera Hpipactis and 
Cephalanthera on account of differences in their floral 
structure. They have creeping rootstocks, and usually 
white or whitish flowers. Instead of the lp being 
continued backwards into a spur, as we find in 
Orchids fertilised by long-tongued insects, in the 
Helleborines it forms a basal basin holding honey, 
more suited to accommodate the heads of wasps and 
flies. The broad-leaved Helleborine (2. latifolia), 
which is not uncommon in woods in July, has its 
ereenish-white flowers marked with purple and yellow. 
The anther is hinged to the top of the column, and 
the pollen masses are powdery, but the pollen-grains 
are so glutinous that they cannot fall upon the 
prominent stigma. A wasp may take his fill of 
honey without touching any irritable surface or 
getting pollinia attached to his head, but when he has 
had sufficient nectar and prepares to go, his head must 
come in contact with them, and he is not allowed to 
go away without taking them with him to fertilise 
the next spike. There appears to be no possibility of 
self-fertilisation occurring, and so impressed by this 
_ fact was Darwin that he declared E. latifolia must 
become extinct in any district where wasps ceased to 
exist. 
