CLASS CRTPTOQAMIA. 187 



283. The order Pentandkia contains the hemp, hop, &c. 

 Fig. 157 represents the flowers of the hemp {Cannabis sativa) ; 

 at a is the staminate flower^ containing five stamens, calyx 

 deeply five-parted, corolla wanting. At Hs a pistillate flower 

 with its calyx opening laterally ; c shows the same flower divest- 

 ed of its calyx ; the seed, a nut crowned with two styles. The 

 hemp belongs to the natural order Urticaceoi (from urtica^ a 

 nettle); the fibers of its stems are manufactured into cloth, 

 cordage, and thread ; the hop, of the same natural family, pro- 

 duces its fertile flowers in large cones or strobilums, formed of 

 membraneous, imbricated scales ; these flowers have a peculiar 

 odor, which produces a narcotic efiect upon the brain. The 

 use of the flowers of the hoj) to produce fermentation in beer is 

 well known. This plant contains a small portion of the nitrate 

 of potash (saftpetre). Hexandria contains the genus Smilax^ 

 the t3rpe of the SmilacecB or sarsaparilla family. Linnaeus con- 

 sidered the species of the Smilax which furnishes the sarsaparilloj 

 a native of the United States only, but it is indigenous to South 

 America. The rhizomes furnish the medicinal parts of the plant. 

 OcTANDKiA contains the poplar (Populus), similar in natural 

 character to the willow. Monadelphia, or the fifteenth order, 

 contains the red-cedar and the yew, which, with the pine and 

 cypress, belong to the cone-bearing family. 



LECTUEE XXXYII 



WANTING. 



284. The Cryptogamous class is the last in the system of 

 Linnseus. The name Cryptogamia implying a concealed union 

 in reference to stamens and pistils is not well chosen, since in 

 some productions belonging to this class there are no evidences 

 of the existence of such organs. We here find the stamens and 

 pistils either wholly concealed from observation, oi* only mani- 

 fest upon the strictest scrutiny. These plants constitute the 

 first class of Jussieu's method called acotyledonous ; their seed 

 being destitute of any cotyledon. As we proceed in this last 

 of the Linnoean classes, we shall find all our former principles 

 of arrangement fail us, and it might almost seem as if we had 

 entered upon a new science. Ferns, mosses, lichens, and 

 mushrooms, constitute the principal families of this class. 



283. Urticaces— Order Hexandria— Octandria— Monadelpliia.— 284. Class Cryptogamia. 



