Humulus

Linnaeus

Sp. Pl. 2: 1028. 175.

,

Gen. Pl. ed. 5, 453. 1754.

Common names: Hop houblon
Etymology: Latin humulus, applied to hop plant
Treatment appears in FNA Volume 3.
 TaxonIllustrator 
FNA03 P72 Humulus Cannabis pg 385.jpegHumulus lupulus var. lupulus
Cannabis sativa
John Myers
John Myers

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.

Distribution

Temperate Northern Hemisphere

Discussion

Species 3 (2 in the flora).

Selected References

None.

Key

1 Veins on abaxial surfaces of leaf blades pubescent, with stiff hairs; marginal areas of adaxial surfaces of younger leaf blades with stiff cystolithic hairs; petioles usually longer than blades; margins of pistillate bracteole densely ciliate-hairy; anthers without glands. Humulus japonicus
1 Veins on abaxial surfaces of leaf blades glabrous or with soft pubescence, without straight, erect hairs; marginal areas of adaxial surfaces of younger leaf blades with few or no cystolithic hairs; petioles usually shorter than blades; margins of pistillate bracteole not ciliate-hairy; anthers glandular. Humulus lupulus
... more about "Humulus"
terete +  and lenticular +
Ernest Small +
Linnaeus +
Hop +  and houblon +
compound +  and staminate +
pendent +  and erect +
(10-)20-100+-flowered +
Temperate Northern Hemisphere +
Latin humulus, applied to hop plant +
pistillate +, staminate +  and short-pedicellate +
paired +  and solitary +
loosely +  and covered +
transitional-bisexual +  and unisexual +
2-branched +  and stalked +
pistillate +  and staminate +
pendent +  and erect +
unlobed +, lobed +  and cordate +
alternate +  and decussate +
compound +  and staminate +
pendent +  and erect +
mottled +  and brownish +
accrescent +
Sp. Pl. +  and Gen. Pl. ed. +
whitish +  and greenish +
hypogynous +
hypogynous +
armed +  and branched +
filiform +
triangular +
resin-dotted and×or gland-dotted +
Humulus +
Cannabaceae +
rhizomatous +  and taprooted +
perennial +  and annual +
rightward-twining +
rhizomatous +  and taprooted +
perennial +  and annual +