2. Sicyos glaber Wooton, Bull. Torrey Bot. Club. 25: 310. 1898.
Smooth bur cucumber Smooth bur cucumber
Stems sparsely villous with flattened hairs mixed with glandular-puberulent vestiture, becoming sparsely hirsutulous to glabrous. Leaves: petiole 1–3(–4.5) cm; blade pentagonal-angulate to reniform-angulate or shallowly 5-angulate, sinuses 1/4–1/3 to base, (3–)4–7 × 5–9 cm, terminal lobe deltate-acuminate, base concave to semicircular, margins evenly subfoliaceous-apiculate, ciliate, surfaces hirsute-hispidulous; proximal pair of lateral veins closely parallel to slightly divergent from edge of basal sinus. Inflorescences: staminate 6–22-flowered, peduncle plus floral axis 15–100(–140) mm; pistillate 4–10-flowered, peduncle 5–8 mm. Flowers: staminate: corolla greenish yellow to yellow, 2–4 mm, stamens slightly exserted; pistillate: sepals not foliaceous, mostly narrowly triangular, 0.5–1.5 mm, corolla 2–3 mm including tube; stigmas 2-lobed. Pepos ovoid, 4–6 mm, not echinate, glabrous or sparsely villosulous.
Flowering Aug–Sep. Canyon bottoms, open slopes, talus, dry drainages, sycamore, juniper-mountain mahogany woodlands, chaparral; 1800–2400 m; N.Mex., Tex.
The distribution of Sicyos glaber in the United States suggests that it also occurs at least in Chihuahua, Mexico, but apparently it has not been documented from there.