Monographs Details – Vascular Plants of the Osa Peninsula, Costa Rica

Monographs Details:

Authority:

Sleumer, Hermann O. 1984. Olacaceae. Fl. Neotrop. Monogr. 38: 1-159. (Published by NYBG Press)

Family:

Olacaceae

Scientific Name:

Heisteria acuminata (Humb. & Bonpl.) Engl.

Synonyms:

Rhaptostylum acuminatum Humb. & Bonpl., Heisteria cyanocarpa Poepp., Heisteria celastrinea Triana & Planch., Heisteria rhaptostylum Triana & Planch., Heisteria pallida Engl., Heisteria burchellii Hochr., Heisteria ixiamensis Rusby, Heisteria longipes Standl., Heisteria macrophylla Oerst., Heisteria guianensis Engl., Heisteria cyathiformis Little, Heisteria cyanocarpa subsp. occidentalis Cuatrec.

Description:

Species Description - Arborescent glabrous shrub or treelet, (1.5-)3-6(-15) m tall, occasionally tree to 20 m, trunk to 20 cm diam., with elongate or drooping branches; bark gray, cracking in squarish plates. Branchlets slender, smooth, terete, pendulous, the youngest parts only subangular. Leaves oblong to elliptic- or lanceolate-oblong, apex shortly subcaudate-acuminate, tip subacute, base cuneate in general, rarely obtuse, chartaceous to subcoriaceous, flexible, slightly shiny above, rather dull and often glaucous-greenish to light brown beneath when dry, neither tuberculate nor wrinkled, laticifers discolorous and usually well visible beneath, variable in size even in the same specimen, (7.5-) 10-14(-23) x (2.5-)3.5-5(-7) cm, midrib slightly or not raised above, strongly prominent beneath, lateral nerves 6-8(-10, very rarely -12) pairs either rather straight below and curving more upwards, or all curved-ascending, the upper 4 or 5 pairs distinctly inarching, plane or rarely a little impressed above in dry specimens, raised beneath, reticulation of veins and veinlets rather densely and finely prominent on both surfaces, or sometimes less so beneath; petiole transversely rugulose, (0.7-) 1-1.5(-2) cm long. Flowers usually rather few per axillary small multibracteolate cushion or axes (1-2 mm long) from foliate or often defoliate branchlets, very rarely from older branches or trunk; pedicels slender, 2-4(-6) mm longicalyx cup-shaped, lobes ovate-acuminate, ca. 1 mm long. Petals ovate-lanceolate, acute, white, hairy inside, (2-)2.5 mm long. Stamens 10; filaments flattish. Ovary conical-ovoid, thickened below. Drupe oblongoid, sometimes broadly or slightly obovoidly so, smooth or with a few, rarely rather numerous tubercles of the endocarp which show through the pericarp in dry fruits, turning red to bluish-blackish at full maturity, (8-)9-10(-11) x (5-)7(-8) mm. Fruit-calyx orbiculate, shallowly lobed or merely undulate, thin, blood red, expanded 1-1.3 (rarely -1.8) cm diam., strongly reflexed; peduncle slender, 1-2 cm long.

Discussion:

Discussion and Ecology: Widespread in Costa Rica and Panama, Colombia, Venezuela, Ecuador, and mainly Amazonian Brazil and Bolivia; in understory of lowland and lower montane rain or cloud forest, also in secondary forest, generally on not-inundated, rarely on periodically flooded ground, often along rivers, to ca. 1800 m alt.