LXXXI. ORCHIDACEjE. 435 



LXXXI. ORCHIDACEJE. THE ORCHID FAMILY. 



Perennial herbs, with the roots or stock often thickened into 

 tubers, entire and parallel-nerved leaves, and irregular flowers, 

 either solitary or in spikes, racemes, or panicles, each one in the 

 axil of a bract. Perianth superior, irregular, with 6 usually 

 petal-like segments ; the 3 outer ones, called sepals, and 2 of 

 the inner ones, called petals, often nearly alike ; the third inner 

 one, called the Up or labellum, differing from the others in shape 

 or direction. Opposite to the lip, in the axis of the flower, is the 

 column, consisting of 1 or rarely 2 stamens, combined with the 

 pistil ; the 2-celled anther or anthers being variously situated on 

 the style itself. Pollen rarely granular, more frequently cohering 

 into 1 or 2 pairs of oblong or globular pollen-masses, tapering at 

 one end into a point. Ovary inferior, 1 -celled, with 3 parietal 

 placentas. Capsule 3-valved, with innumerable minute seeds, 

 resembling fine sawdust. 



A very extensive Order, spread over all parts of the globe. Our own 

 species, and generally those of temperate regions, are terrestrial, but a 

 large proportion of the tropical ones are epiphytes, growing upon the 

 stems and branches of trees, but without penetrating into their tissues. 

 Numbers of these are now extensively cultivated for the singularity of 

 the forms assumed by the flowers, as well as for their great beauty. The 

 genera are distinguished chiefly by the form and relative arrangement 

 of the anther-cells, the pollen masses, and the stigma, and the shape 

 and direction of the lip, characters which, however essential, are in 

 many cases as difficult to describe clearly as to observe accurately, 

 especially in dried specimens. For the beginner, therefore, I have en- 

 deavoured in the following table to select such prominent features as 

 may guide him to the British species, independently of the more minute 

 characters, which may be reserved for subsequent study. 



Stem without any leaves, except short scales. 

 Lip with a spur underneath. Flowers few, rather large . S. Epipogum. 

 Lip without a spur. Flowers small. 

 Plant green. Flowers white, in a spirally-twisted spike . 9. Spiranthes. 

 Plant and flowers brown or yellowish-white. Flowers 

 in a raceme. 



Lip entire, not so long as the sepals 3. Corallorhiza. 



Lip 2-cleft, longer than the sepals ..... 7. Neottia. 

 Plant with 1, 2, or more green leaves. 

 Perianth with a spur or pouch at the base of the lip . . 11. Orchis {and 

 Perianth without any spur or pouch* 12. Habenaria). 

 Lip hanging, longer th%7i the sepals, very narrow or divided 

 into narrow lobes. Flowers yellowish-green. 

 Stem with 2 opposite, broad leaves. Flowers pedicel- 

 late. Rootstock fibrous 6. LlSTERA. 



* A single specimen has been occasionally found of species of Orchis and Habe- 

 naria, in which the flowers are all deformed, without any spur, but such instances 

 are very rare. 



