The great tribe of British Neotteæ is characterized by a free anther standing like a hood behind the stigma; the pollen grains are tied together with threads, and attached to a viscous cap lying on the top of the rostellum. The Epipactis palustris is a type of this group of orchids. Its spike is short, and the pink blossoms stand out horizontally from the stem on long ribbed footstalks, which contain the ovaries. Fig. 83 A is a side view of the flower in its natural position, with the lower sepals alone removed. The labellum, or lowest petal, is interrupted in the middle by a kind of flexible hinge: the basal part is a cup-shaped trough, at times abounding in nectar; the extreme part is a wavy leaf (fig. 83 B). The entrance to the nectary cup is nearly closed by the hood and the large anther; but, on account of the elasticity of the hinge, the weight of an insect is sufficient to give access to the nectar; but no sooner is the labellum relieved of the weight, than it springs up into its natural position, and the insect creeps backwards and comes out at the top of the flower with the viscous cap clasped round its proboscis, and the pollen grains attached to it ready to fertilize another blossom. In fig. 84, C represents a section of the Epipactis, and D is a front view of the column. [Illustration: Fig. 85. Listera ovata:—Side view of flower, with sepals and petals cut away: _a_, anther; _col_, summit of column; _p_, pollen; _r_, rostellum; _s_, stigma; _l_, labellum; _n_, nectar-secreting furrow.]