Annual herbaceous vine to 6 m or longer Stem: slender, high-climbing, angled, sometimes hairy at nodes. Leaves: alternate, long-stalked, 7 - 13 cm long, heart-shaped to egg-shaped or nearly circular, having three to seven deep lobes (usually five) with pointed tips, non-toothed or few-toothed. Flowers: either male or female, found on the same plant (monoecious), greenish-white, the calyx with six bristle-like lobes, the corolla flat and circular in outline and ending in six lance-shaped lobes. Male and female flowers are borne in the same leaf axils, but the male flowers are arranged in a 30 - 40 cm long inflorescence while the female flowers are solitary or in pairs. Fruit: green, 3 - 5 cm long, egg-shaped, fleshy at first, becoming dry and papery, inflated, covered with slender weak spines, opening irregularly at the tip, releasing four seeds. The flattened seeds are brownish and 1.2 - 1.5 cm long with a hard and roughened coat. Tendrils: branched.
Similar species: Sicyos angulatus differs by having shallowly lobed leaves, a five-lobed corolla, and fruit that is not inflated, does not open at maturity, and contains a single seed.
Flowering: late July to early October
Habitat and ecology: Frequent in low areas such as floodplains and moist thickets.
Occurence in the Chicago region: native
Notes: Echinocystis lobata was once cultivated to cover arbors or fences and has been known to escape fom gardens.
Etymology: Echinocystis comes from the Greek words echinos, meaning hedgehog, and kystis, meaning bladder, referring to the prickly fruit. Lobata means lobed.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
Infrequent in low ground along streams and about lakes and ponds throughout the state although there are no published records from the southwestern part. Sometimes cultivated as an ornamental vine.
High-climbing annual; lvs long-petioled, orbicular in outline, with (3-)5(-7) sharp, triangular lobes; staminate fls in long erect racemes, the cor 8-10 mm wide, with lanceolate lobes, the pistillate few or solitary, short- peduncled from the same axils; fr ovoid, 3-5 cm, green, weakly prickly; 2n=32. Moist ground and thickets, throughout our range and s. to Fla. and Tex.; often cult. July-Sept. (Micrampelis l.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.