Ipomoea sinuata Ortega, alamo vine. Perennial vine, twining; shoots with only cauline leaves, axes pilose and hairs with swollen bases (pustulate), blades glabrous, with cloudy latex.
Stems cylindric, to 3 mm diameter, tough, internodes to 150 mm long.
Leaves helically alternate, deeply palmately–5–divided with 5 principal lobes, basal pair asymmetric having a sublobe and other lobes pinnately lobed, petiolate, without stipules; petiole cylindric, 15—65 mm long, pilose; blade roundish to ovate in outline, 30—80 × 20—50 mm, principal lobes divided to below midpoint, lobes ovate in outline above webbed base, dentate on margins, acute at tip, principal veins palmate for lobes, each lobe pinnately veined with principal veins sunken on upper surface and conspicuously raised on lower surface.
Inflorescence 1—2–flowered cyme, axillary, > leaf, bracteate, pilose; peduncle + pedicel to 100 mm long, peduncle 45—50 mm long, wiry, pilose hairs to 5 mm long and bumps from hair bases; bractlet subtending pedicel awl–shaped, ca. 5 mm long, green with membranous margins, abscised with truncate base; pedicel cylindric, at anthesis 35—40 mm long, green, bumpy to warty and with irregular short ridges.
Flower bisexual, radial, 45—53 mm across; sepals 5, overlapping, outer 2 sepals 21—25 × 14 mm increasing to 35 × 21 mm in fruit, green at base and greenish to whitish above midpoint, with conspicuous swellings at bases, middle sepals with 1 basal bump; corolla broadly 5–lobed, widely funnel–shaped, ca. 40 mm long; tube ± 10 × 4.5 mm, cream–colored, with decurrent bases of filaments inside tube, outer surface broadly 5–ridged and soft short–hairy, lower throat rose–red on inner surface, with 5 fine parallel veins to each lobe tip, lobes acute at tip, white to pinkish above red; stamens 5; filaments fused to corolla, unequal, 7—10.5 mm long, rose to midpoint and pale pink above, glabrous; anthers dorsifixed, dithecal, ca. 7 mm long, white, longitudinally dehiscent; pollen white; nectary disc surrounding base of ovary, 0.5 mm long, white; pistil 1; ovary superior, ovoid shallowly 4–lobed, ca. 2 × 2 mm, white, glabrous, 2–chambered, each chamber with 2 ovules; style included ca. 22 mm long, cream–colored, glabrous; stigmas 2, spheroid, 0.7—0.8 mm, white.
Fruit capsule, hidden by persistent sepals, 4–valved, to 4–seeded, ovoid, ca. 30 × 25 mm.
Seed ovoid 3–sided, 8—13 × 8—11 mm, black, rounded on back with 2 flat sides.
A. C. Gibson