From Common Forest Trees of Hawaii

Pithecellobium dulce
Pea family (Fabaceae)

Post-Cook introduction

This tree, introduced about 1870 for shade in dry lowlands, has become naturalized. It is identified by paired sharp spines usually present at base of leaf, twice leaves with 4 oblong small creamy white flowers in balls of 3⁄8 inch (1 ), and curved or coiled pink to brown pods with several shiny black seeds mostly covered by whitish pulp. Mimosa subfamily (Mimosoideae).

W. John Hayden
This is a small to medium-sized tree to 60 ft (18 ) high and 2 ft (0.6 ) in trunk diameter, the short trunk and branches often crooked, with broad spreading and slender drooping twigs. Nearly but shedding old leaves as new pinkish or reddish foliage appears. Bark light gray, smoothish, becoming slightly rough and furrowed. Inner bark is thick, light brown, and bitter or astringent. Twigs slender and drooping, greenish and lightly hairy when young, becoming gray, covered with many small whitish dots (lenticels).

Leaves with pair of slender, sharp spines () 1⁄16–5⁄8 inch (1.5–15 ) long usually present at base, very slender green leafstalk of 1⁄4–1 1⁄2 inches (6–38 ) with tiny round near and 2 lateral axes () only 1⁄8–1⁄4 inch (3–6 ) long. four in pairs, nearly stalkless, oblong or 1⁄2–2 inches (13–50 ) long and 3⁄16–5⁄8 inch (5–15 ) wide, rounded at the oblique base rounded or short-pointed, not on edges, thin or slightly thickened, hairy or hairless, dull pale green above, and light green beneath.

Flower clusters (heads) many, short-stalked in slender drooping or lateral axes, each covered with whitish hairs and composed of 20–30 densely hairy flowers. Each flower has tubular hairy five- about 1⁄16 inch (1.5 ) long; funnel-shaped tubular hairy five- about 1⁄8 inch (3 ) long; about 50 spreading long threadlike united into short tube at base; and with hairy and threadlike

Pods 4–5 inches (10–13 ) long, 3⁄8–5⁄8 inch (1–1.5 ) wide, slightly flattened, inconspicuously hairy. Seeds are beanlike, elliptical, 3⁄8 inch (1 ) long, hanging down from open pod, inside pulpy edible mass (aril) as much as 3⁄4 inch (2 ) long. With flowers in spring and from April to June.

Sapwood is yellowish, and heartwood yellowish or reddish brown. Wood is moderately hard, heavy, strong, and durable. It takes a high polish but is brittle and not easily worked.

Elsewhere, the wood is employed for general construction, boxes and crates, posts, and fuel. The bark has been harvested for its high tannin content. It also yields a yellow dye and is an ingredient in home remedies. A mucilage can be made by dissolving in water the transparent deep reddish brown gum that exudes from the trunk.

The thick whitish sweetish acid pulp around the seeds can be eaten or made into a drink. Livestock browse the pods under the trees. The flat black seeds are strung into leis in Hawaii. The tree is also a honey plant. This attractive species makes a good highway and street tree, especially in dry areas, growing rapidly and enduring drought, heat, and shade. It withstands close browsing and pruning and is suitable for fences and hedges. Formerly, it was a popular street tree in southern Florida. However, it was susceptible to hurricane damage and did not recover well.

In Hawaii, this species is planted and naturalized in pastures and waste places through the dry lowlands. It is of frequent occurrence along the highway near Haleiwa, Oahu, and in the scrub forest near Lahaina, Maui. One cultivated form has variegated green and white leaves. Degener (1930) reported that the false mynah bird eats the fleshy seed covering and spreads the seeds. According to Neal (1965), the Hawaiian name ‘opiuma is from the resemblance of the seeds to the opium of commerce.

Height 66 ft (20.1 ), c.b.h. 24.9 ft (7.6 ), spread 107 ft (32.6 ) Napoopoo, Hawaii (1968).

Mexico (Baja California, Sonora, and Chihuahua southward) through Central America to Colombia and Venezuela. Widely planted and naturalized in New and Old World tropics. Introduced in southern Florida and Puerto Rico and Virgin Islands.

Other common names
gaumuchil, Manilatamarind, Madras-thorn; guama americano (Puerto Rico); guamuche (Mexico, commerce); kamachili (Guam, N. Marianas); kamatsiri (Palau)

This species was named and described botanically in 1795 from Coromandel, India, where it had been introduced. The specific name, meaning sweet, refers to the edible seed pulp.

stamen -- the pollen-producing reproductive organ of a flower; The stamen consists of an anther supported by a filament.

cm -- A centimeter which is about 0.4 inches.

m -- A meter is about 10% larger than a yard.

Glands are plant structures that secrete liquids, salts or other substances. Glands often appear as hairs with a drop of liquid at the end.

stipule -- A leaf-like structure that occurs where the leaf joins the stem; stipules often occur in pairs.

style -- This is a long and thread-like structure that connects the stigma with the ovary. A flower may have a single style, or several of them.

The apex is the tip or the furthest point from the attachment.

alternate -- leaves alternate along the main stem and are attached singly.

terminal -- Located at the end (the tip or the apex).

Like the teeth on a saw, leaves and other surfaces can have toothed edges.

A pistil is the female structure of many flowers. It contains one or more carpels. Each carpel contins an ovary, style and stigma. The stigma receives the pollen which grows thru the style to reach the ovary.

Bipinnate -- A compound leaf with two rows of leaflets where those leaflets are again compound with two rows of leafelets.

An evergreen tree retains a large portion of its green leaves all year.

pinnae -- the primary segments of a compound leaf.

calyx -- the sepals of a flower, typically forming a whorl that encloses the petals and forms a protective layer around a flower in bud.

fruit -- any seed-bearing structure in flowering plants. It is formed from the ovary after flowering.

canopy -- The foliage of a tree; the crown. Also the upper layer of a forest.

leaflets -- Each little leaf-like thing in a compound leaf is a leaflet.

mm -- millimeter. About 1/25th of an inch.

corolla -- The name for all the petals of a flower taken together.

ovate -- Oval, egg-shaped, with a tapering point.

pinnate -- A compound leaf with two rows of leaflets.

An ovary is a part of the female reproductive organ of the flower. Above the ovary is the style and the stigma, which is where the pollen lands and germinates to grow down through the style to the ovary.