Form: A tree with a spreading habit.

Lifespan: 50-150 years.

Leaf retention: Semi-evergreen, with new leaves quickly replacing old ones as they drop, once a year.

Growth rate: Rapid.

Mature Size: 20-30' (6-9m) high with a spreading habit.

Flowers: White to cream, fragrant, frizzy puffballs, 1/2" (1.27cm) across.

Bloom: Spring.

Self-fruitful: Yes.

Years before fruiting: 4, grown from seed in optimal conditions.

Fruit: A curly, knobby bean pod with a thin, brittle shell. The white to red popcorn-like filling, surrounding 5-12 shiny, edible black beans, has a sweet-tart flavor variously described as apple-coconut or dried pineapple-peach. It is used to make a drink similar to lemonade.

Months for fruit to ripen: 2-4. The pod is ripe when it reddens and splits open. As the split widens, the seed and its surrounding pulp, attached by a cord-like structure, fall out, displaying the seed to birds and tree climbing animals.

Storage after harvest: After pod splitting, the pulp can be consumed immediately or allowed to dry a few days before being used. The flavor can be more intense when the pulp is dried.

Leaves: Green, oval, in groups of four leaflets, with thorns at their base. Dense shade.

Stems: The trunk and branches are thorny, especially when young, with irregular branching. The bark is initially gray to gray-brown, and over many years becomes rough, furrowed and eventually peeling. The branches are susceptible to breakage in strong winds.

Roots: An initial seedling tap root is followed by nitrogen fixing, aggressive, lateral roots that dominate the root system of the mature tree. Injury to the roots results in thorny suckering. After five years in the ground, the tree may regrow from its roots in severe freezes.

Wildlife: The flowers attract honeybees. The tree is a caterpillar food plant for some species of butterflies and moths. Birds and climbing animals may be attracted to the open pods and their contents.

Toxic / Danger: Thorns. The sap and bark can cause severe eye irritation.

Origin: Coastal regions from Mexico through Central America into adjacent South America.

USDA hardiness zones: 10-11. It may die in freezes when young.

Chill hours: None.

Heat tolerant: Yes.

Drought tolerant: Yes, when mature.

Sun: Full sun. This plant is shade intolerant when young.

Planting: Plant in the first half of spring before high temperatures arrive, in full sun, in an area where it can grow to its natural size without pruning. It should have 12-15' (3.7-4.5m) clearance on all sides. A south-west exposure is best to minimize winter freezes.

Soil: Guamuchil is tolerant of soil types, and moderately saline tolerant.

Fertilize: Do not use a fertilizer containing nitrogen because the roots of this plant are nitrogen fixing.

Water after becoming established: Deep water every few weeks.

First Year Care: Protect from freezing in the first three years, including using winter mulch. Deep water every 1-3 days in summer and twice a month in winter. Keep other plants and grass away from its root area.

Prune: This plant is somewhat thorny and pruning substantially increases the thorniness. Older trees seem to have fewer thorns. It can be pruned as a hedge by cutting close to the ground (coppicing), causing it to turn very thorny and becoming a livestock barrier.

Litter: Leaf fall during annual leaf changeover, bean pods.

Propagation: Rooted cuttings, cuttings grafted onto seedling rootstock. Seed germinates quickly, but is only viable for six months and does not grow true to its parent.

Uses: Light shade, edible bean pod filling and beans, barrier hedge. The bean pods are used as animal feed. The seeds produce a green oil for culinary use or soap making.
To make guamuchil syrup, simmer the guamuchil pulp in one cup water plus one cup sugar for a few minutes and then allow to cool. Add to ice water for a refreshing drink. The guamuchil flavor dissolves better in hot water than alcohol, which can be later mixed with the syrup.

Pithecellobium dulce means "sweet monkey earring".

Look carefully at the left side of the trunk in the bottom picture and you will see two small thorns. Four others are also visible, one as a shadow.

This plant is distantly related to other Legume family plants with edible bean pods or filling, such as Carob, Pacay, and Tamarind.

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