Herbs, perennial or annual, twining, dioecious. Stems, branchlets, and petioles with rigid 2-armed stalked hairs. Stems coarse, 6-ridged or winged. Leaves opposite, well developed leaves ± cordate and 3-7(-9)-lobed, terminal leaves sometimes ± ovate and simple, abaxially with yellowish brown resinous glands and dots. Male inflorescences laxly paniculate. Male flowers: filaments straight in bud; female inflorescences a conelike spicate cyme; bracts imbricate, persistent and enlarged in fruit, margin entire. Female flowers: calyx thinly membranous, appressed to ovary, margin entire; ovary ± surrounded by appressed calyx; styles 2-branched; branches caducous. Achene broadly ovoid; calyx persistent, appressed to achene; pericarp crustaceous; embryo spirally involute; cotyledons narrow.
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.
"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."
Small, E. 1978. A numerical and nomenclatural analysis of morpho-geographic taxa of Humulus. Syst. Bot. 3: 37-76. Small, E. 1980. The relationships of hop cultivars and wild variants of Humulus lupulus. Canad. J. Bot. 58: 676-686.
|Hop, houblon [Latin humulus, applied to hop plant]|