Terminalia buceras aka Black Olive

Terminalia buceras is an evergreen tree in the Combretaceae family. Its common names include black olive and oxhorn bucida. RHS lists Bucida buceras as a synonym. It is not the olive grown for food. Its native range spans central Mexico, the Caribbean, and Colombia’s San Andrés Island. Sources disagree about its native status in the Florida Keys. It grows in coastal woods, limestone forests, and near streams. Some populations also grow in brackish marshes.

In gardens, it reaches 40–50 feet [12.2–15.2 metres] tall. Its crown spreads 35–50 feet [10.7–15.2 metres] wide. Useful Tropical Plants gives a broader height range of 30–59 feet [9–18 metres]. It also reports trees reaching 108 feet [33 metres]. Young trees have a pyramid shape around an upright trunk. Older crowns become dense, round or oval, and sometimes flat-topped. Strong branches resist wind damage, though they may droop. Smooth brown bark grows rough and cracked with age. Slender gray-brown twigs may bear short spines. Simple, leathery leaves cluster near the branch tips. They have smooth edges and dark green upper surfaces. The undersides are paler, with no showy fall color change.

Small flowers appear in spring and summer on narrow spikes. They are cream to pale yellow and shaped like urns. Their scent draws bees, which pollinate the flowers. Small fruits ripen from mid to late summer. They hang in clusters and become dark brown or black. Fallen fruit and leaves create litter beneath the crown. Fruit releases tannins that can stain paving and parked cars. UF/IFAS reports that the fruit does not draw wildlife.

Grow this tree in full sun or partial shade. It prefers moist soil that drains well. It tolerates sand, loam, clay, and acidic or alkaline soil. High soil pH can cause yellowing leaves. Established trees have strong drought and salt-spray tolerance. Sources conflict on growth speed, describing both fast and slow growth. UF/IFAS places it in USDA zones 10b–11. Slight cold damage can occur at 32°F; 25°F can kill it. Pruning helps build a sound branch structure.

Garden uses include shade, specimen planting, hedges, and street planting. Its hard, heavy timber and tannins have other uses. Traditional remedies use bark and leaves for fever. Useful Tropical Plants lists no known food uses or hazards. That does not prove safety for people or pets. Major pest and disease problems are uncommon. Sooty mold and bark borers sometimes occur. Mites cause galls that need no control, according to UF/IFAS. In South Florida, UF/IFAS advises management to prevent escape.