1. Echinocystis lobata (Michx.) Torr. & A. Gray (wild cucumber)
Sicyos lobata Michx.
Micrampelis
lobata (Michx.) Greene
Map 1628, Pl.
372 d
Plants
monoecious annual vines with slender taproots. Stems to 5 m or more long,
slender (1–2 mm in diameter), glabrous, not roughened, the tendrils branched.
Leaves mostly long-petiolate, the petiole 1–4 cm long, lacking glands at the
tip, glabrous or nearly so. Leaf blades 2–8 cm long, 3–12 cm wide, broadly
ovate to nearly circular in outline, palmately moderately 5-lobed, the lobes
triangular to oblong-triangular, with sharply pointed tips and mostly narrowly
rounded (less than 90°) sinuses, cordate at the base, the margins otherwise
sparsely toothed, the surfaces glabrous or slightly to moderately roughened
with minute, nonsticky, pustular-based hairs (often only the small, hardened
bases apparent). Flowers solitary or in small, few-flowered clusters
(pistillate) or in well-developed racemes or racemelike panicles (staminate) 8–14
cm long in the leaf axils, the main stalk of the pistillate inflorescence 2–5
mm long, the clustered flowers with individual stalks 1–5 mm long. Calyx lobes
1.0–1.5 mm long. Corollas 8–12 mm wide, saucer-shaped to broadly bell-shaped,
the usually 6 lobes 3–6 mm long, white to cream-colored. Staminate flowers with
the filaments fused into a tube (the anthers usually free). Pistillate flowers
usually lacking staminodes, the ovary with usually 2 ovules per placenta, the
stigma bluntly 2- or 3-lobed. Fruits solitary, thin-walled berries, more or
less inflated and juicy at first but becoming dry and fibrous inside a papery
wall at maturity, dehiscing irregularly at the tip with age, 2.0–3.5 cm long,
ovoid or ellipsoid, with a stalk 9–35 mm long, the surface green, covered with
slender (often bristly), relatively soft, straw-colored to pale yellow prickles
3–6 mm long, otherwise glabrous. Seeds usually 4, 12–20 mm long, 6–9 mm wide,
elliptic-obovate to more or less elliptic in outline above a short, stalklike
base, flattened, usually pointed at the tip, the surface otherwise shallowly
and irregularly pitted, dark brown, often finely mottled. 2n=32. June–October.
Scattered mostly
in the western half of the Unglaciated Plains Division sporadically south to
Jasper and Greene Counties and east to the city of St. Louis (eastern U.S. west
to Montana and Texas; Canada; introduced west to Washington and Arizona). Banks
of streams and rivers and bottomland forests; rarely roadsides and disturbed
areas.
Wild cucumber
occasionally is grown as an ornamental on arbors for its showy staminate
inflorescences and attractive foliage. It can escape from cultivation. Native
Americans used an infusion of the species to treat fevers, rheumatism,
headaches, and general pain, and to induce abortion (Moerman, 1998). With age,
the large bristly fruits burst irregularly at the tip and the seeds are
dispersed explosively under hydrostatic pressure.