Flora of Barro Colorado Island

Zanthoxylum procerum

Donn. Sm., Bot. Gaz. (Craw­fordsville) 23:4.1897

Alcabú, Ikor, Lagarto

Dioecious tree, 8-17 (20) m tall; trunk to 18 cm dbh armed, the prickles corky, conical, with the sharp apex usually slightly off-center, the sides with weak vertical grooves; branches sparsely armed with short prickles; outer bark with lenticels arranged in irregular vertical streaks; inner bark tan; twigs soon glabrous. Leaves al­ternate, imparipinnate or paripinnate, 12-45 cm long (to 60 cm on juveniles), glabrous; petioles 1-10 (14) cm long, the pulvinus moderately small to much expanded; rachis canaliculate above, especially beneath insertion of each leaflet; petiolules 3-7 mm. long; leaflets (2)      4-18, unarmed, mostly opposite, sometimes alternate especially basally, broadest in middle, narrowed gradually to either end, gradually acuminate at apex, cuneate to attenuate with both sides ± equally decurrent at base, 4.5-14.5 cm long, 1.5-5 cm wide (to 25 cm long and 8 cm wide on juveniles), the margins usually minutely crenate and conspicuously pellucid-punctate, the surfaces ± shiny and glabrous, with numerous, minute, lepidote scales on both surfaces, lacking pellucid dots except near margin, often somewhat viscid when dried. Panicles terminal, 10-20 cm long, the branches many, sparsely puberulent, densely lenticellate and punctate, with markedly con­stricted articulations at the base at maturity; flowers uni­sexual, with sweet aroma, ca 2 mm long, 3-parted; calyx lobes triangular; petals broadly oblong, rounded at apex; staminate flowers with the stamens 5, well exserted, 2-3 mm long, the pistillode minute, conical, the style short; pistillate flowers unknown. Fruits of 1 brown follicle, 3-3.3 mm diam, globose, densely covered with lenticels and minute glandular projections, on a short stalk ca 7 mm long, the valves 2, persistent, translucent, hydro­scopic, dehiscing at maturity, folding together laterally to expel seed; seed 1, rounded, ca 3 mm diam, black with brown reticulations. Croat 11670, 12189.

Frequent in the forest. Flowers from February to May (sometimes from January). The fruits mature from June to November, mostly in August and September. Allen (1956) reported this species to flower in August and Sep­tember in the Golfo Dulce area of Costa Rica, although he was possibly dealing with a different species.

Distinguished by the small, glabrous leaves, which are acute at the base, and the three-parted flower. Cut parts of the plant have a very strong odor similar to that of the citron fruit, and the flowers have a sweet odor. The valves of the fruit are capable of expanding and contracting repeatedly during alternate periods of high and low humidity.

Southern Mexico to Panama. In Panama, known from tropical moist forest in the Canal Zone, Panama, and Darién and from premontane wet forest in Chiriqui (Progreso) and Panama (Cerro Campana). Reported from tropical wet forest in Costa Rica (Holdridge et a1., 1971).

See Fig. 298.

Photos from STRI Digital Archive

  • Zanthoxylum procerum