Common Hop

Hop has been reported to be cultivated in N.W. Himalayas and Kashmir. Used. for brewing and in medicines.

Until recently, knowledge of the existence of indigenous kinds of North American Humulus lupulus was uncertain, although the appellation American hop was applied sometimes to H . lupulus var. neomexicanus and sometimes confusingly to other hop varieties. The distinctive Japanese variety H . lupulus var. cordifolius (Miquel) Maximowicz has not been collected from North America. Hops cultivated commercially in North America for flavoring alcoholic beverages are forms of the European H . lupulus var. lupulus . The European variety may have been introgressed by one of the American varieties.

Humulus lupulus has often been transplanted from the wild to homesites as an ornamental. When such sites are abandoned, the plants often persist, and it may appear that they are present naturally. As well, suppliers of ornamental plants may sell hops collected from one site to buyers in a quite distant site. The hop varieties discussed here may therefore be found occasionally beyond the distribution ranges given in this treatment.

Native Americans used Humulus lupulus medicinally to induce sleep, for breast and womb problems, for inflamed kidneys, rheumatism, bladder problems, intestinal pain, fever, earaches, pneumonia, coughs, and nervousness, as a tonic and a stimulant, and as a witchcraft medicine (D. E. Moerman 1986).

The measurements mentioned in couplet 1 of the following key are taken in the middle abaxial portion of the central lobe on 4-6 cm leaf blades attached to flowering or fruiting twigs.

A number of different varieties is usually recognized (Small, Syst. Bot. 3: 37–76. 1978), with the populations in China represented by at least both H. lupulus var. lupulus, a predominantly European to C and SW Asian variety, and var. cordifolius (Miquel) Maximowicz, a predominantly Japanese variety. In addition, the populations in S Gansu and N Sichuan may possibly be another, distinct variety. Further study is needed to sort out the pattern of varietal occurrence in China, which is complicated by the introduction and escape of cultivated var. lupulus for commercial production of hops for beer.

This species is cultivated throughout China, especially in E Shandong (Qingdao) and Xinjiang. The flowers and infructescences are important ingredients for beer making. The female flowers and bracts are used medicinally.

Clockwise twining climber with stout root stock. Stem 3-6 m. tall, scabrid or prickly. Leaves broadly ovate, more or less cordate at base, usually deeply 3-5 lobed, serrate, 6-12 cm in diameter, lobes acuminate, petiole shorter or equal to blade. Male panicle 7.5-10 cm. in diameter with c 5 mm across flowers. Female inflorescence 12-15 mm. in diameter with yellow flowers; bract 10 mm. long, ovate, acute, pale green ; styles purple. Etaerio of achenes 3-4 cm in diameter.

Herbs , perennial, rhizomatous, 1-6(-7) m. Stems branched. Leaves: petioles usually shorter than blades. Leaf blade ± cordate, palmately 3-7-lobed, sometimes unlobed, 3-15 cm, margins dentate-serrate; surfaces abaxially with veins glabrous or with soft pubescence, without straight, erect hairs, glands yellow, adaxially margins of younger leaf blades with few or no cystolithic hairs. Inflorescences: staminate with flowers whitish to yellowish, anthers glandular; pistillate usually racemes, 10-20 mm, pedunculate; bracteole margins not ciliate-hairy. Infructescences pendulous, pale yellow, conelike, ovoid to oblong, (1-)2-3(-6) cm; bracteoles with yellow glands. Achenes yellowish, ovoid, compressed, glandular. 2 n = 20, including 2 or more sex-determining chromosomes.

Plants perennial. Petiole usually shorter than leaf blade; leaf blade 3-5(-7)-lobed, sometimes simple, 4-11 × 4-8 cm, abaxially glabrous or with scattered soft pubescence but without rigid spinulose hairs on veins, adaxially with few or no cystolith hairs marginally when young, base cordate, margin coarsely serrate, apex acute. Female flowers 2 per bract at least in middle of inflorescence; bracts imbricated into a globose spike. Infructescences globose, 3-4 cm in diam.; bracts ovoid, 1.5-2 cm, dry, membranous, apex acute. Achenes flat, included in bracts. Fl. autumn.

Distribution: North America, South Europe, Western Asia.

Gansu, N Sichuan, Xinjiang [N Africa, N and NE Asia, Europe, E North America].