178 CLASS GYNANDRIA. 



to the character of thick and branching fibres, all of 

 which are annually and laterally renewed, so that in 

 many of the tubers, as those of Aplectrum and Epi- 

 dendrum, the annually rejected, inert, and withering 

 tubers form concatenated links of several individuals, 

 possessing different degrees of vitality, and power of 

 reproducing plants. Nearly all the genera, however, 

 except those with fibrous or clasping roots, appear to 

 be of slow and difficult propagation, and are, there- 

 fore, but seldom successfully cultivated ; nor will many 

 of them exist at all except in the shade of the forest, and 

 amidst recent vegetable soil. — The leaves of the whole 

 tribe are invariably entire, not even so much as serrat- 

 ed on the edges, and commonly of an oblong or ellip- 

 tic form, and wholly or partially, as in grasses, embrac- 

 ing the stem by their base. The stems or scapes are 

 simple or undivided ; and the flowers arranged in 

 spikes or racemes. In all, the corolla, for there is no 

 calyx, is referrible to a division into 6 parts, as in the 

 Lilies ; but these are of different forms, and in several 

 combinations ; 5 of these parts are always external, 

 but frequently in 2 ranges, as in Orchis, where the 

 3 external resemble a calyx, and there are then 2 

 internal divisions like petals, conniving together beneath 

 one of the external segments, so as to resemble a hood 

 or helmet. The 6th segment or lip, for they always ap- 

 pear ringent flowers, possesses the most varied forms, 

 being a perfect vegetable Proteus. It is collocated op- 

 posite to the style, which is often petaloid, and seems 

 then to form an upper lip in accordance with the low- 

 er, or true petal. In Orchis this Gth petal or lip is 

 often trifid, more rarely simple, and sometimes divid- 

 ed into fringe or hairs ; its base terminates in a sac oi' 

 elongated nectariferous cavity, called the spur. In 

 the Cypripedium or Ladies'-slipper, which has mostly 

 2 of its petals ingrafted so as to appear but one, with 



