THE GREATER BUTTERFLY ORCHIS— continued. 
The two tubercles of the root are ovoid, each tapering into a fibrous point, or, 
as Parkinson puts it, “like small turnips.” The stem is angular; the two lower 
leaves are from three to six inches long, elliptical, tapering to a sheathing base, 
spreading, and of a lustrous unspotted green. A third, smaller, and more upright 
leaf is commonly present ; whilst Parkinson’s “ peeces ” are the lanceolate bracts on 
the lower part of the stem. The bract below each flower is only about the same 
length as the twisted inferior ovary and is green. The spike is generally lax, i.e. 
the flowers are not crowded together, and each blossom measures fully an inch from 
the tip of the odd sepal to that of the labellum. The three sepals spread widely and 
the whole flower is, as most of its specific names have suggested, tinged with a 
yellowish green. This colour is, however, accompanied by the delicious fragrance, 
so frequent among white flowers, which becomes much more powerful in the 
evening — an indication of the agency of crepuscular moths as fertilisers. The length 
of the spur, which is twice that of the ovary, i.e. from twenty to forty millimetres, is 
another indication of the dependence of the flower upon Lepidoptera for its 
pollination. The two petals are small, blunt, and “ connivent,” or converging in an 
arch, and the labellum of the third is straight, linear-oblong, blunt, entire, and rather 
longer than the sepals. The two anther-chambers are widely separated by the abrupt 
semicircular termination of the style and are twice as far asunder at the base as they 
are at their apex ; but there is no rostellum between them. The pollen-masses 
are yellow, club-shaped, and have long caudicles and round retinacula. Darwin 
found that the adhesive matter on the retinaculum retains its adhesive property 
for twenty-four hours. While the pollinia slope backward their retinacula stand 
forward on either side of, and in advance of, the stigmatic surface. Each retinaculum 
is prolonged backwards into a short drum-like portion or “ pedicel,” as Darwin 
termed it, to which the caudicle of the pollinium is attached. This pedicel plays a 
very important part in pollination, since it contracts on one side on being removed 
from the anther, and thus brings the pollinium into such a position that it will strike 
the stigma of the next flower to which it is carried. The retinacula in this species 
attach themselves to the eyes or sides of the face of the visiting moths, whereas 
those of H. bifolia , the Lesser Butterfly Orchis, attach themselves to the base of the 
insect’s proboscis. 
