Description

Key Characters:

Growth Form: Trailing or climbing annual herbs.

Stems: Stems up to several m long, villous with glandular hairs.

Roots:

Leaves: Leaves simple. Alternate. Blades broadly ovate to reniform with a broad basal sinus, 7–12 cm long and wide, shallowly palmately 5–lobed, the lobes broadly triangular. Apex short-acuminate. Surfaces scabrid with short white hairs; lower surfaces more densely so. Margins minutely denticulate. Petioles 3–14.5 cm long. Stipules absent; tendrils in the stipular position 4–5–branched.

Flowers: Flowers in staminate flowers in sparsely glandular pubescent panicles 15–20 cm long, peduncles 8–10 cm long, pedicels 3–5 mm long; pistillate flowers 24–30 per head, sessile on peduncles 1.3–4 cm long. Flowers usually unisexual (and the plants monoecious or dioecious), actinomorphic. Calyx of 5 sepals; sepals inserted on hypanthium. Corolla of staminate flowers 5-lobed, ca. 5 mm in diameter, glandular, petals inserted on hypanthium alternate with calyx lobes, usually connate at base, the limb often rotate; Corolla of pistillate flowers 5-lobed, perianth usually smaller than in staminate flowers. Stamens in staminate flowers 5, inserted at base of hypanthium; filaments connate into a column; anthers curved or flexuous, coherent and twisted in a head, opening by longitudinal slits; pistillate flowers: staminodes absent. Ovary inferior (pistillate flowers); stigma 3-lobed or 5-lobed, the lobes reflexed.

Fruit: Fruit pale brown; obovoid; attenuate; 9–10 mm long; 5–6 mm in diameter; puberulent; toward apex bearing ascending sparsely puberulent outgrowths 3–4 mm long; abruptly contracted into a short beak. Seeds 1 per fruit; ovate; endosperm absent.

Ploidy:

Habitat: Known only from the type collection (Long 2370; BISH) from Laysan; in herb community with Ipomoea pes-caprae; on coral sand.

Elevation Range: near sea level.