Humulus

Herbs , taprooted annuals or rhizomatous perennials, rightward-twining. Stems usually branched, armed with rigid 2-branched, stalked hairs that facilitate climbing. Leaves simple; petioles often twining, with 2-branched hairs. Leaf blade mostly cordate, palmately lobed, sometimes unlobed; surfaces abaxially resin-dotted and×or gland-dotted. Inflorescences: staminate inflorescences axillary and terminal, cymose panicles, erect to pendent, (10-)20-100+-flowered, flowers small; pistillate axillary, spikes or racemes, flowers solitary or paired, short-pedicellate, subtended by bracts and bracteoles. Staminate and pistillate flowers usually on different plants. Achenes lenticular or terete, ensheathed by brownish or sometimes mottled persistent perianth; embryo coiled. x = 10.

PLANT: Usually twining, dioecious herbs with harsh forked hairs. LEAVES: simple, palmately lobed or unlobed, the abaxial surface often resin dotted. INFLORESCENCE: staminate inflorescences axillary or termi¬nal, 20-100-flowered; pistillate inflorescence axillary. FLOWERS: pistillate flowers paired, subtended by bracts and bracteoles. FRUIT: lenticular, enclosed by persistent perianth. x=10. REFERENCES: Mason, Charles T., Jr. 1999. Cannabaceae. Ariz. - Nev. Acad. Sci. 32(1).

Dioecious; pistillate fls in short spikes, paired, each pair subtended by a foliaceous bract; ovary enclosed by the membranous, lobeless cal; fr an achene enclosed in the persistent cal and covered by the accrescent bracts; twining, herbaceous, perennial vines with rough stems and broad, opposite, usually lobed lvs. 3, N. Temp.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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