Zanthoxylum fagara aka Lime Prickly Ash

Zanthoxylum fagara, or wild lime, is in the citrus family, Rutaceae. It grows in the tropics and subtropics of the Americas. Its range takes in south Florida and the Caribbean. It also grows in Central and South America. Wild plants grow in woods, clearings, and at forest edges. In south Florida, they grow under trees behind coastal dunes. Elsewhere, they grow on dry sand or moist forest soil.

Wild lime forms a shrub or small tree. It grows at a moderate rate. Garden trees reach 15–25 feet [4.6–7.6 metres] tall. Their crowns spread 15–20 feet [4.6–6.1 metres] wide. Broader accounts give heights of 39 feet [12 metres]. The crown may be round or more open. Several trunks often rise near the ground. Growers can train plants to have one short trunk. Young twigs are thin and brown. Sharp spines can cause painful wounds.

The green leaves grow alternately, one after the next. They are odd-pinnately compound: leaflets share a stalk, with one at its tip. Clear wings run along this stalk, called the rachis. Crushed leaves give off a lime scent. The leaflets have rounded teeth and widen toward their tips. Florida sources say the leaves stay green year-round. They report no change in leaf colour in autumn. Other accounts say plants shed some of their leaves. Small yellow flowers bloom at times throughout the year. Insects pollinate them, but the species is not self-fertile. It cannot set seed with its own pollen alone. The round black fruits stand out. They measure under 0.04 feet [0.013 metres] across.

Wild lime grows in part shade or full sun. Trees in sun form fuller, more even crowns. It copes with sand, loam, and clay. These soils can be acid or alkaline. It stands up well to drought. Reports say it also copes with floods in some seasons. Its stated hardiness range is USDA zones 9b–11. Its small garden size suits patios and pots. It also fits sites with little space for soil. It serves as a specimen or border tree. People also plant it by roads. Butterflies visit the plant.

University of Florida reports no serious pests or diseases that limit growth. Roots rarely cause problems. It has no reported tendency to spread invasively there. Useful Tropical Plants lists no known edible uses or hazards. This does not mean every part is safe to eat. The spines still pose a clear risk of harm. That source also notes medicinal use of bark, leaves, and roots. It gives no details of those treatments. People harvest its long-lasting wood for building and poles. They also use it for turned work and cabinets.