ISS CLASS GYNANDRIA. 



Orchis tribe of Plants. 



Tlie natural order, Orchideae, is composed of genera which be- 

 ong to the class Gynandria ; the principal of these is the Orchis 

 genus, the different species of which are mostly perennial, and grow 

 in moist and shady places ; some are parasites, adhering to the bark 

 of trees by their fleshy, fibrous roots. The roots sometimes con- 

 sist of two solid bulbs, in other cases, they are oblong, fleshy sub- 

 stances, tapering towards the ends like the fingers of the hand. The 

 fiame Orchis is derived from a Greek word, signifying an ohve-ber- 

 /■y, on account of the root being round, like that fruit. The distin- 

 guishing characters of this tribe, are a corolla, above the germ, 5 

 petals, 3 external and 2 internal. There is also in each corolla, a 

 ,i*,tal-hke organ called the lip, which varies in form and direction ; 

 jfiulhers always 1 or 2, and from 1 to 4-celled, sessile, or sitting upon 

 the side or apex of the style ; the pollen is easily removed from the 

 cells in glutinous masses ; the styles are simple, with viscous stigmas 

 of various forms and positions. The capsules are 1-celled, 3-valved, 

 3-keeled ; the seeds are numerous and dust-like, the leaves clasp the 

 stem like the leaves of grasses. The stems or scapes are simple, 

 and the flowers are arranged in spikes or racemes. 



This natural order has monocotyledonous seeds, and stamens epi- 

 gynous, or above the germ. The flowers are remarkable for their 

 irregular, and we might add, grotesque appearance ; some present 

 the figure of a fly, others of a spider, a bird, and even of the 

 human figure. It would seem too that the freaks of these vegeta- 

 ble beings are not designed for our observation, for they are as 

 peculiar in their choice of habitations as in their external forms, 

 preferring wildness, barrenness, and desolation to the fostering care 

 of man, or the most luxuriant soil. It is in forests of the equatorial 

 regions, that these plants appear in the greatest perfection. The 

 aromatic vanilla is obtained from the fruit of a cUmbing orchis of 

 those regions. 



The Orchis genus has a nectary in the shape of a horn ; its co- 

 rolla is somewhat ringent, the upper petal vaulted, the lip is spread- 

 ing, the 2 masses of pollen are concealed at the sides, by little sacs, 

 or hooded hollows of the stigma. 



Fig. 146 represents a flower of this genus ; a, shows the two 

 masses of pollen, brought out from the cells of the anther, which is 

 attached to the pistil. 



Order Diandria 



The 2d order contains the ladies' slipper, (Cypripedidm ;) the nec- 

 tary or lip is large, inflated, and resembles a shpper. We have 

 several species of this curious plant, some of which are yellow, 

 some white, and others purple. 



Order Pentandria. 



The 5th order contains the milk-weed, (Asclepias;) this by some 

 botanists is placed in the fifth class, on the supposition that the sta- 

 mens do not proceed from the pistil. 



Order Hexandria. 



The 6th order contains the Virginia snake-root, (Aristolochia 

 serpentaria,) a perennial plant, with brown fibrous roots ; it is found 

 in shady woods, from New-England to Florida: the root is highly 

 valued in medicine; it possesses an aromatic smell, somewhat simi- 

 lar to spruce. It is said to have been found, by a chemical analysis, 



Natural order Orchideae— Distinguishing characters of this family— Orchis— Order 

 Diandria— Order Pentandria— Order Hexandria— Virginia snake-root. 



