Havana clustervine

Convolvulus havanensis Jacquin, Observ. Bot. 2: 25, plate 45, fig. 3. 1767; Jacquemontia jamaicensis (Jacquin) Hallier f. ex Solereder

Vines, perennial, sometimes forming dense thickets. Herbage hairy, hairs stellate, 6- or 7-armed, arms unequal, porrect. Stems proximally woody, radi­ating from stout rootstock, prostrate, scrambling, or climbing, forming a dense tangle, 2–3 m. Leaf blades (in flora area,) elliptic or slightly ovate, 10–35 × 8–15 mm, ± herbaceous to subcoriaceous, base cuneate, apex acute to obtuse, mucronate. Inflorescences lax, 1–6+-flowered. Flowers: sepals ± equal or slightly unequal, outers ovate or broadly elliptic, 2–4 mm, glabrous, inners broadly ovate to suborbiculate, 2–3 mm; corolla white, light pink, or pale violet, rotate, 8–15 mm, limb deeply incised, 5-lobed. Capsules subglobose, 4–6 mm. Seeds 2–3 mm, outer 2 margins narrowly winged, wings 0.1–0.2 mm wide, striate, undulating. 2n = 20.

Flowering Aug–Jun. Coastal beach dunes, berms, rockland hammocks; 0–10 m; Fla.; Mexico; West Indies; Central America.

Jacquemontia havanensis is widespread throughout the Bahama Islands and Greater Antilles, barely reach­ing the Florida Keys, the Leeward Islands, Mexico, and Central America. It, J. curtissii, J. reclinata, and the West Indian J. cayensis Britton are closely related and form a distinctive group. All have a stout rootstock from which arise a number of radiating, horizontal stems that decline, scramble, or twine on other vegetation. Some lateral branches may be erect, and the inflorescences are also erect. Other characteristics are the mostly elliptic to suborbiculate leaf blades, 3–7-armed, stellate hairs, inflorescences usually not exceeding the leaves, deeply incised corolla limbs, and seeds with narrow, prominent wings or ridges on the two outer margins.