Annual herbaceous vine to 6 m or longer Stem: climbing. Leaves: alternate, hairy-stalked, heart-shaped to circular in outline, toothed, sharply angled or having three to five shallow lobes with pointed tips. Flowers: either male or female, found on the same plant (monoecious), small, white or greenish, the calyx five-toothed, the corolla flat and circular in outline and five-lobed. Male flowers are borne in loose inflorescences, while female flowers are borne in small dense clusters. Fruit: borne in clusters, about 1.5 cm long, egg-shaped, dry, not inflated, covered with prickly bristles, not breaking open at maturity, one-seeded. Tendrils: branched.
Similar species: Echinocystis lobata differs by having deeply lobed leaves, a six-lobed corolla, and inflated fruit that opens at the tip and contains four seeds.
Flowering: July to late September
Habitat and ecology: Occasional in low or floodplain woodlands, frequent in the Kankakee River valley.
Occurence in the Chicago region: native
Etymology: Sicyos is the Greek word for cucumber. Angulatus means angular.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
Probably found throughout the state. It prefers moist soil along streams in open woodland and in cultivated fields. It is rare in the northern part of the state, becoming abundant in cornfields in the Lower Wabash Bottoms where it is regarded as one of the most objectional of all weeds because the spines of the fruit stick through clothing, and in husking corn the hands of workmen are injured.
Climbing sometimes to several m; lvs orbicular in outline, shallowly 3-5-lobed, usually with a deep basal sinus, the lobes denticulate, acuminate; pistillate peduncles eventually 5-8 cm, the staminate usually longer; staminate cor 8-10 mm wide, lobed to the middle; fr ovoid, 1.5 cm, hairy and spiny; 2n=24. Damp soil; Me. and Que. to Minn., s. to Fla. and Ariz. July, Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.