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Sapindus oahuensis
Alternative Botanical Names
Sapindus lonomea
Common Names
O'ahu Soapberry
Potential or Traditional Uses
Lei (Flower or Seed)
Photo of Sapindus oahuensis
Sapindus oahuensis is a tree ranging in height from 20 to 50 feet. It has rough light gray to white bark on older branches, but the youngest ones are covered with yellow brown fuzz. The oval leaves are green with a yellow midrib. They have the texture of thick paper and range in size from 3 to 10 inches long. The edges of the leaves are somewhat wavy.

The flowers grow in clusters from the bases of the leaf stems. The flowers are unisexual, but both male and female flowers are produced on the same plant. (Wagner 1990)

Habitat and Geographic Range
Sapindus oahuensis is endemic of the islands of Kaua'i and O'ahu. It grows in moist to dry forests at elevations of 200 to 2,000 feet. It occurs in northwestern Kaua'i, in O'ahu's Wai'anae Mountains, and from Waimalu to Niu Valley in the Ko'olau Mountains on O'ahu. (Wagner 1990)
Propagation by Seeds
The fleshy fruit of Sapindus oahuensis is brown-black, oblong, and ranges in size from 3/4 to 1 1/4 inches. The fruits generally ripen in the fall and winter. Each fruit contains 1, sometimes 2, oval, wrinkled, black seeds. The seeds are 3/8 inch to 3/4 inch long. Sapindus oahuensis appears to be self-compatible.

Best germination is obtained with fresh, mature seed. Remove the seed from the fruit flesh. Discard any seeds that have insect damage or that float in water.

Bornhorst says that scarification is not required to improve germination. However, Lilleeng-Rosenberger recommends scarifying the seeds using a clippers, file or sandpaper, or cracking them with a hammer being careful not to damage the end where the seed will sprout. Some of Stratton's survey respondents recommended scarification using a file followed by soaking in hot water for 1 hour or tepid water for 24 hours.

Koebele recommends the following procedure for treating seeds of Sapindus oahuensis. The seeds should be scarified with a clippers or a knife. Following scarification, the seeds can either be kept in clean, moist verimulite for 1 or 2 weeks, or be soaked in a shallow pan of water until the dark outer seed coat is soft. If the seeds are soaked, the water should be changed daily. Once the outer coat has softened, it can be removed by hand or with a small knife and then the thin papery brown inner coat should be carefully peeled off. This procedure leaves the cream colored embryo exposed. Handle the embryo carefully so that the embryonic root is not damaged. The embryo should be planted immediately in sterile potting soil, burying it 3/8 to 3/4 inch deep. With this method, Koebele has found that germination takes place in about a week and the germination rate is almost 100%. Germination of untreated seeds or of seeds which have only been scarified takes 1 to 6 months and the germination rate is variable since the seeds tend to rot.

Some of Stratton's respondents also recommended removal removing all of the seed coats and using the embryo for propagation. They recommended a planting the prepared seeds in a shallow container using a fast draining, sterile medium such as a mixture of 3 parts #2 perlite to 1 part Sunshine Mix #4. The medium should be kept moist and the container put in a shaded area until germination. Placing the container under cover will allow better control of soil moisture and prevent rain damage.

Cleaned, air dried seeds can be stored in a paper bag or envelope placed inside an airtight container with desiccant. They should be kept in a cool place at 25% relative humidity. (Bornhorst 1996; Culliney 1999; Koebele 1998; Stratton 1998; Wagner 1990)

Propagation by Cuttings
No information located to date.
Propagation by Division
Not applicable.
Propagation by Air Layers
No information located to date.
Propagation by Grafting
No information located to date.
Propagation by Tissue Culture
No information located to date.
Bornhorst, Heidi L. 1996. Growing native Hawaiian plants: a how-to guide for the gardener. Honolulu: The Bess Press. p. 56-57.

Culliney, John L., and Bruce P. Koebele. 1999. A native Hawaiian garden: how to grow and care for island plants. Honolulu: University of Hawai'i Press. p. 53-55.

Koebele, Bruce P. 1998. A highly effective method for germinating aulu/lonomea (Sapindus oahuensis). Newsletter of the Hawaiian Botanical Society 37 (3):46.

Lilleeng-Rosenberger, Kerin. 1998. Propagation techniques for native Hawaiian plants. Newsletter of the Hawaiian Botanical Society 37 (2):33-35.

Stratton, Lisa, Leslie Hudson, Nova Suenaga, and Barrie Morgan. 1998. Overview of Hawaiian dry forest propagation techniques. Newsletter of the Hawaiian Botanical Society 37 (2):13, 15-27.

Wagner, Warren L., Darrel R. Herbst, and S. H. Sohmer. 1990. Manual of the flowering plants of Hawai'i. 2 vols, Bishop Museum Special Publication 83. Honolulu: University of Hawaii Press and Bishop Museum Press. p. 1229.

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The image in this record is used with permission from Dr. Gerald Carr's Web site "Hawaiian Native Plants" at

Last updated:
7 October 2001

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