From Common Forest Trees of Hawaii

Wingleaf Soapberry
Sapindus saponaria
Maple family (Sapindaceae)

Native species (indigenous)

This handsome tree is of special interest as one of two tree species native to both Hawaii and the continental United States (southern Florida). (The other is ‘a‘ali‘i, Dodonaea viscosa Jacq.). It is characterized by leaves with usually 6–12 paired elliptical to lance-shaped dull green and axis slightly winged when young and by the shiny brown ball-like single-seeded berries 5⁄8–3⁄4 inch (15–19 ) in diameter.


©2013 Eric White
A small to large tree becoming 80 ft (24.4 ) tall in Hawaii and as much as 6 ft (1.8 ) in trunk diameter, larger than elsewhere, with enlargements or buttresses at base, and with compact Bark light brown or gray, smoothish and warty, becoming finely fissured, shedding in large and exposing smooth dark layer. Inner bark is light orange brown, slightly bitter and astringent. Twigs stout, light gray with raised reddish brown dots (lenticels), finely hairy when young.

Leaves 8–16 inches (20–40 ) long. stalkless or nearly so, 2 1⁄2–5 inches (6–13 ) long and 3⁄4–1 1⁄2 inches (2-4 ) wide, long or short-pointed at base short-pointed or blunt and often oblique and unequal with side toward leaf broader, not on edges, thin, upper surface dull green and hairless, lower surface slightly paler and sometimes soft hairy.

Flower clusters () and lateral, to 4–8 inches (10–20 ) long, larger elsewhere, very numerous small 5-parted whitish flowers 3⁄16 inch (5 ) across, mostly male but some female or (polygamous). Male flowers have five spreading unequal about 1⁄16 inch (1.5 ) long, outer two smaller, whitish and tinged with green; five white hairy rounded petals smaller than eight light yellow more than 1⁄16 inch (1.5 ) long on a light green and minute brown nonfunctional Female flowers have petals, shorter and greenish more than 1⁄16 inch (1.5 ) long with three-celled and slender

(berries or cocci) are in clusters on hard woody stalks, single (sometimes two or three), developing from a and others -like at base, with leathery shiny brown skin and yellow sticky bitter poisonous flesh, clear or translucent. Seed single, round, black, 3⁄8–1⁄2 inch (10–13 ) in diameter, poisonous.

Sapwood is whitish and heartwood yellow or light brown. Wood hard and heavy ( gr. 0.8), coarse-textured, and not durable when exposed. Elsewhere used for posts and in carpentry.

The scientific and common names refer to the use elsewhere of the fleshy as a substitute for soap. When cut up, the fleshy part, containing about 30 percent saponin, produces abundant suds in water.

The seeds are used in leis in Hawaii. In tropical America, crushed seeds serve as a fish poison when thrown into a stream. An insecticide has been made from ground seeds, and medicinal oil extracted. Also elsewhere, the hard round seeds have been used as beads in necklaces and rosaries as well as marbles and formerly, as buttons.

A common shade tree in tropical America and classed as a honey plant. Infusions of the roots and leaves have been prepared for home remedies.

Wingleaf soapberry is native in the middle forest zone at 3000–4500 ft (914–1372 ) elevation on the island of Hawaii, for example, Mauna Loa and Puu Waawaa. The trees of largest size are accessible and easily seen in Kipuka Puaulu near Kilauea Volcano within Hawaii Volcanoes National Park. There are also some at Ulupalakua on Maui. Another form is planted in Hawaii as a shade tree.

Special areas
Waimea Arboretum, Wahiawa, Volcanoes, Kipuka Puaulu, Ala Moana Park

Champion
Height 106 ft (32.3 ), c.b.h. 10.1 ft (3.1 ), spread 84 ft (25.6 ). Hawaii Volcanoes National Park, Hawaii (1968).

Range
Widespread in tropical America from northern Mexico to Brazil and Argentina and through West Indies including Puerto Rico and Virgin Islands. Also in Florida and at 2 coastal localities in Georgia, the range extended northward partly by prehistoric Indians and partly by cultivation. Native to Hawaii and other Pacific Islands including the Marquesas and Society Islands to New Caledonia. Introduced into Old World tropics.

The native Hawaiian trees found in 1909 by Joseph F. Rock seemed different from the introduced trees of another form in Honolulu and were named Sapindus thurstonii Rock. Soon afterwards he concluded that the native trees, which have foliage, were the same as the species widespread on the American continent. The segregate was revived by St. John (1977b).

The separate or distribution of this tree species in continental America and also Hawaii and other Pacific Islands is unexplained. However, Degener (1930, p. 202) observed that the dried berries have an air space between the outer wall and seed formed by the shrinking flesh and that they will float in water. Also when removed from the at least half of the seeds will float. Thus, long distance transportation by ocean currents may occur. Seeds are often found in beach drift on various islands. Rock found that the Hawaiian trees attain a larger size, both in height and particularly in trunk diameter, than those anywhere on the mainland.

Other common names
a‘e, manele, soapberry; jaboncillo (Puerto Rico, Spanish)

Botanical
Sapindus thurstonii Rock

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

cm -- A centimeter which is about 0.4 inches.

Flowers with both stamens and pistils are bisexual. Also called "perfect flowers".

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

disc flowers are those in the center of a sunflower or daisy. Not a ray flower.

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.

scale -- A very small leaf around a dormant bud. Also other things that might remind one of fish scales on the surface of ferns, stems and the like.

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 panicle is a much-branched inflorescence. The bottom flowers in a panicle open first.

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.

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

disjunct -- Occuring widely in separated areas, as in disjunct plant populations.

deciduous plants are those that lose all of their leaves for part of the year.

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.

synonym -- In botany a synonym is a species name that at one time was thought to be the correct name for a plant but was later found to be incorrect and has been replaced by a new name.

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

sp. -- The abbreviation for "species". The plural is "spp". When used it sometimes means that the exact species is unknown. For example, "Aster sp" would mean some species within the Aster genus but the writer may not know exactly which species.

Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom.

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.