Only 2 genera with 3 species (Asiatic), of which two are cultivated.--_Humulus lupulus_ (Hop, Figs. 347–349) is a twining, perennial plant, twisting to the right, with opposite, palmilobed, rough leaves, and large, interpetiolar stipules. The ♀-flowers are situated in closely-flowered, cone-like, compound inflorescences, with ultimately large, thin, imbricate floral-leaves (Fig. 348) which bear the yellow, glandular hairs, containing lupulin. ~This inflorescence is made up as follows:--The most external floral-leaves are situated in pairs, and are the persistent stipules of a leaf, the blade of which has become suppressed, or in any case is rudimentary. Such a pair of stipules supports 4 (2–6) flowers in a double uniparous cyme, whose central axis does not develope into a flower. The bracts of these flowers (bracteoles of the partial inflorescence) become, at maturity, very large, spathe-like, and, together with the stipules, produce a cone-like appearance.~ [Illustration: FIG. 347–348.--_Humulus lupulus_: 347, twining stem; 348, branch with strobiles.] _Cannabis sativa_ (Hemp, Figs. 350–353) is an East Indian herb, with palmilobed leaves, and differs from the Hop in being annual, erect, and in having its leaves opposite at the base and scattered above. The ♀-inflorescence is not cone-like as in the Hop, but the flowers are similar in construction. ~The main difference is to be found in the axillary shoot, which was suppressed in the Hop, and is in the Hemp developed into a leaf-bearing shoot which on each side bears only one ♀-flower, and in the fact that the bracts are not so strongly developed.~ The “Hops” (the female inflorescences) are used in brewing, and medicinally on account of the yellow glands which contain lupulin. The Indian variety of _Cannabis sativa_ contains an abundance of glandular hairs and resin. The withered inflorescences are used in medicine and are officinal. The bast of the stems of the Hemp is also used and the fat oil of the seeds. In Oriental countries the entire plant is used in the preparation of an intoxicating drink (haschisch), the narcotic material being found in the glandular hairs. [Illustration: FIG. 349.--_Humulus lupulus_: fruit in longitudinal section.] [Illustration: FIGS. 350–353.--_Cannabis sativa_: Fig. 350, ♂-plant; Fig. 351, ♂-flower; Fig. 352, ♀-flower, entire and in longitudinal section; Fig. 353, fruit in longitudinal section.] Family 6. =Polygonifloræ.=