Amphitecna latifolia: Black Calabash

Introduction

This upright, densely foliated, evergreen small tree can reach a height of 30 feet with a variable spread. The large, seven-inch-long, dark green, glossy leaves make it ideal for a small-scale shade or specimen tree, or it can be allowed to grow into a tall screen. Throughout the year, two-inch-long, purplish-white, non-showy tubular flowers are produced on short stalks. These blooms are followed by smooth, shiny green, four-inch-long fruits which have a thin, hard shell and contain numerous 1/2-inch-long, edible black seeds in white pulp. The furrowed tree bark is grey and rough.

General Information

Scientific name: Amphitecna latifolia

Pronunciation: am-fih-TECK-nuh lat-ih-FOLE-ee-uh

Common name(s): Black Calabash

Family: Bignoniaceae

USDA hardiness zones: 10B through 11 (Fig. 2)

Origin: not native to North America

Invasive potential: little invasive potential

Uses: deck or patio; screen; shade; specimen; parking lot island < 100 sq. ft.; parking lot island 100–200 sq. ft.; parking lot island > 200 sq. ft.; tree lawn 3–4 feet wide; tree lawn 4–6 feet wide; tree lawn > 6 ft. wide; highway median

Availability: somewhat available, may have to go out of the region to find the tree

Description

Height: 25 to 30 feet

Spread: 15 to 25 feet

Crown uniformity: irregular

Crown shape: oval, upright/erect

Crown density: dense

Growth rate: moderate

Texture: medium

Foliage

Leaf arrangement: alternate (Fig. 3)

Leaf type: simple

Leaf margin: entire

Leaf shape: oblong, elliptic (oval)

Leaf venation: pinnate, brachidodrome

Leaf type and persistence: evergreen, broadleaf evergreen

Leaf blade length: 4 to 8 inches

Leaf color: green

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: purple

Flower characteristics: not showy

Fruit

Fruit shape: round

Fruit length: 3 to 6 inches

Fruit covering: fleshy

Fruit color: green

Fruit characteristics: does not attract wildlife; not showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches don't droop; showy; typically one trunk; thorns

Pruning requirement: needed for strong structure

Breakage: susceptible to breakage

Current year twig color: gray

Current year twig thickness: thin, medium

Wood specific gravity: unknown

Culture

Light requirement: full sun, partial sun or partial shade

Soil tolerances: clay; sand; loam; alkaline; acidic; well-drained

Drought tolerance: high

Aerosol salt tolerance: high

Other

Roots: not a problem

Winter interest: no

Outstanding tree: no

Ozone sensitivity: unknown

Verticillium wilt susceptibility: unknown

Pest resistance: free of serious pests and diseases

Use and Management

Growing in full sun or partial shade on a wide range of soils, black calabash has only marginal salt-tolerance and is very susceptible to wind damage. Top-heavy trees are known to blow over in high winds. Be sure to untangle circling or kinked roots before planting to help prevent this from occurring. Proper branch thinning can also help prevent this from occurring.

Propagation is by seed, cuttings, or air-layerings.

Pests and Diseases

No pests or diseases are of major concern.