12. Sicyosperma A. Gray, Smithsonian Contr. Knowl. 5(6): 62. 1853.
Climbing arrowheads [Greek sikyos, cucumber or gourd, and sperma, seed] Climbing arrowheads [Greek sikyos, cucumber or gourd, and sperma, seed]
Plants annual, monoecious, climbing; stems glabrous or sparsely puberulent; roots fibrous; tendrils 2-branched. Leaves: blade broadly to shallowly triangular, usually shallowly palmately 3(–5)-lobed to hastate, lobes triangular to deltate, margins entire or denticulate, surfaces eglandular. Inflorescences: staminate flowers 20–40 in axillary, compound racemes; loosely enclosing flowers, irregularly sinuate-dentate to incised>. Flowers: hypanthium cupulate; sepals 5, filiform-subulate; petals 5, connate 1/3–1/2 length, white, triangular-lanceolate, 1–1.5 mm, stipitate-glandular along margins, without other hairs, corollas salverform. Staminate flowers: stamens 3; filaments inserted at hypanthium base, connate into central column; thecae connate, forming head, sigmoid, connective slightly broadened; pistillodes absent. Pistillate flowers: ovary 1-locular, ovoid; ovules 1 per locule; style 1, narrowly columnar; stigmas 1, capitate, 3-lobed; staminodes absent. Fruits pepos, whitish, ellipsoid-ovoid, <compressed, dry at maturity>, smooth, <glabrous>, indehiscent. Seeds 1, ovoid, compressed, not arillate, margins not differentiated, surface smooth.
Species 1: sw United States, nw Mexico.
