HUMULUS, the hop: A genus of the pentandra order, belonging to the dioecia class of plants; and in the natural method ranking under the 53rd order, Sambucideae. The male calyx is pentaphyllous; there is no corolla; the female calyx is monophyllous, patent obliquely, and entire, there is no corolla; but two styles; and one seed within the calyx, the latter consisting of one large leaf. There is only one species, viz., the lupulus, which is sometimes found wild in hedges near houses and gardens, but probably is not indigenous. The stalk is weak and climbing; it creeps up the support in a spiral, ascending always from the right hand to the left. The stalk and the leaves are rough to the touch; the upper leaves are heart-shaped, the lower ones divided into three lobes serrated on the edges, and grow in pairs on long footstalks. The male flowers grow on a distinct plant on branched peduncles; the females on peduncles in pairs of the form of a fibrobus or cone, composed of large imbricated calyces containing each one or two seeds. For the culture and uses of hops, see the articles Hop and Husbandry.