Stems relatively pubescent at nodes, usually more than 15 hairs per 0.1 sq. mm at most pubescent portion (excluding angle of petiole with stem). Leaf blades 10 cm or more usually having fewer than 5 lobes; smaller blades (ca. 5 cm) often with no more than 3 easily visible veins branching off midrib (excluding proximal branches); surfaces abaxially conspicuously pubescent, more than 100 hairs per cm on length of medial midrib, more than 25 glands per 10 sq. mm between veins, hairs present between veins. Moist thickets, woods; 0-1000 m; Ark., Ill., Ind., Iowa, Kans., Md., Minn., Mo., Nebr., N.Y., N.C., Ohio, Okla., Pa., Va. Humulus lupulu s var. pubescens intergrades with other varieties. It is found primarily in the midwestern United States.
Perennial herbaceous vine with rhizomes 1 - 10 m long Stem: twining, branched, relatively hairy at nodes, with rigid, two-branched hairs that help the plant climb. Leaves: opposite, palmately three- to seven-lobed, often unlobed, 3 - 15 cm long, main leaves as wide as long, broadly egg-shaped to more or less heart-shaped with a pointed tip, toothed, usually with hairs between veins beneath, more than 100 hairs per cm along midrib beneath, yellow-glandular. Flowers: either male or female, borne on separate plants (dioecious), small, without petals. Male flowers whitish to yellowish, with five sepals. Stamens five. Anthers glandular. Female flowers short-stalked, subtended by a leaf-like bract. Ovary covered by the membranous, fused sepals (calyx). Stigmas two, thread-like. Fruit: an achene, enclosed inside the persistent sepals, yellowish, egg-shaped, compressed, glandular, covered by bracts. Male inflorescence: an axillary and terminal, cluster (cymose panicle) of flowers, 5 - 15 cm long. Female inflorescence: an axillary spike of two flowers, 1 - 6 cm long, subtended by a leaf-like bract that is straw-colored, blunt, and glandular at the base.
Similar species: The variety lupuloides differs by having mostly three-lobed leaves that do not have hairs between the veins beneath. The similar Humulus japonicus differs by having non-glandular, mostly five- to nine-lobed leaves.
Flowering: August to mid-September
Habitat and ecology: Found on floodplains and in weedy areas under partial shade.
Occurence in the Chicago region: native
Etymology: Humulus comes from the word humus, meaning ground, referring to the trailing habit of this plant. Lupulus means "little wolf." Pubescens means downy.