Flora of Barro Colorado Island

Omphalea diandra

L., Syst. Nat. ed. 10, 2:1264.1759

Monoecious liana, to more than 30 m high in canopy, sparsely pubescent to glabrate all over except on inflores­cence; trunk to 7 cm dbh; outer bark unfissured; inner bark tan with raised white areas on outer surface, the sap violet-purple, often forming droplets between inner bark and wood. Leaves alternate, simple; stipules minute; petioles to 11 cm long, with 2 large round glands at apex; blades ovate to broadly elliptic, bluntly mucronate at apex (rarely abruptly acuminate), rounded to truncate or slightly cordate at base, 8-21 cm long, 5-15 cm wide, entire; veins at base 3-5, the major lateral veins in 2 or 3 pairs. Panicles 10-50 cm long, terminal or upper-axillary, bracteate; bracts biglandular, the basal 2-3 mm long, the apical 2-3.5 cm long and very narrow; branches and bracts densely pubescent; flowers apetalous, green or yellowish, clustered in cymules in 3 possible arrange­ments: with all staminate flowers, with a central pistillate flower and several staminate flowers, or with a solitary pistillate flower at apex of branches; staminate flowers globular; pedicels ca 2 mm long; calyx lobes 4, biseriate, 1.5-2.5 mm long and wide, glabrate and ciliate; stamens 2 (rarely 3); anthers ca 0.7 mm long; pistillate flowers on pedicels 1-2 mm long; calyx lobes 4, ovate, ca 2 mm long and wide, pubescent to glabrate; styles 3, connate, the column stout, densely pubescent, 2-2.5 mm long. Fruits ± round, 8-12 cm diam, fleshy but ultimately dehiscent into 3 woody cocci (fide Flora of Panama); seeds 1 per coccus, compressed-globose, 4-4.5 cm diam, brown or black, slightly rugose. Croat 5236.

Uncommonly encountered in the forest and at the margin of the lake. Since the plant is a high-canopy vine with inconspicuous flowers, it might be more common than collections and observations indicate. Flowers mostly throughout the dry season and in the early rainy season. Nearly mature-sized fruits are seen late in the dry season, probably dehiscing in the early rainy season. Leaves fall for at least a short time in the middle of the dry season.

The fruits are reported to be capsular, but I have never seen them open. They are possibly mammal dispersed or, as some have suggested, in part water dispersed, since the plant perhaps grows more frequently near water. Larvae of the moth Urena fulgens (Urenidae) are leaf-miners apparently restricted to this species (Neal Smith, pers. comm.).

Honduras to Peru and Brazil; West Indies. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Veraguas, Panama, and Darien and from tropical wet forest in Chiriqui.

See Fig. 324.

Photos from STRI Digital Archive

  • Omphalea diandra fruit
  • Omphalea diandra seed-wet
  • Omphalea diandra
  • Omphalea diandra
  • Omphalea diandra