Native Plants of Hawai‘i - Dodonaea viscosa

Dodonaea viscosa

Sapindaceae or Soapberry family

Synonyms: Dodonaea arborescens var. spatulata, Dodonaea eriocarpa, Dodonaea sandwicensis, Dodonaea spatulata, Dodonaea stenoptera, Dodonaea x fauriei

ʻAʻaliʻi

ʻAʻaliʻi kū ma kua, ʻAʻaliʻi kū makani, Kūmakani

Hawaiian hopseed bush

Natural Range & Environment

Dodonaea viscosa is indigenous to all the main Hawaiian Islands, growing in a variety of habitats such as lava ridges and fields, pastures, coastal dunes, low-elevation shrublands, and dry, mesic, and wet forests, as well as subalpine shrublands, from 3-2,350 m (10-7,710 ft) Pantropic, that is, it is found throughout the tropics of the world [Wagner et al. 1990].

ʻAʻaliʻi is an extremely variable native shrub growing in a wide range of habitats. Some are very low-growing shrubs under 60 cm (2 ft) tall, such as these forms with reddish or white and pinkish capsules on Lānaʻi gathered by Doreen Hobdy for lei, while others grow as small trees growing over 7.5 m (25 ft) tall. Using a low-growing ʻaʻaliʻi with ʻiliahiolʻe, pōhinahina, along with other natives, presents a natural-looking landscape, as seen here in a neighborhood park on Oʻahu. Close-ups of male flowers and a hermaphroditic plant with both male flowers and female fruits. (Photographs of male flowers and hermaphroditic plant courtesy of G.D. Carr ©). ʻAʻaliʻi tree form (Photograph courtesy of Forest & Kim Starr CC BY 3.0 US).

Description

Dodonaea viscosa is a highly variable species not only in Hawaiʻi but also throughout its entire range. This plant can take on various forms, with some growing as low shrubs reaching heights of 60 cm (2 ft), while others can grow into small trees towering over 7.5 m (25 ft) tall. The leaves of this species can range from short and narrow to long and narrow in shape, and color can range from light to dark green to red or reddish purple.

The flowers of Dodonaea viscosa are small and often go unnoticed, with some plants bearing male, female, or hermaphroditic flowers. However, it is the female plants that develop the distinctive multi-sided winged or box-shaped fruits, containing small black or brownish seeds when mature. Capsules can be from straw-colored to dark reddish purple, exceedingly variable with 2-4 wings. Fruits do not retain their color. Some ʻaʻaliʻi plants are known to flower and fruit capsules almost continuously throughout the year.

Growth Requirements

General

ʻAʻaliʻi is a low-maintenance shrub or small tree that can be a beautiful addition to any landscape or garden, serving as an accent, screening, or hedge. It thrives in dry, sunny conditions and can adapt to various landscape environments. When grown in shade with excess moisture, it tends to become more tree-like or leggy, so it prefers full sun to branch and flower profusely.

ʻAʻaliʻi is tolerant of drought, wind, and salt spray, making it a hardy choice for many different settings. It is not particular about soil type, as long as it is well-draining. Only potted plants require a regular fertilizer regimen.

Many people prefer female ʻaʻaliʻi for their small, colorful boxy capsules. However, the only way to determine the plant's gender is to allow it to mature to the flowering stage. At this point, you can decide whether to keep a male tree or opt for a female-only garden.

For a harmonious landscape, consider pairing ʻaʻaliʻi with other native companion plants such as ʻilima, ʻakia, kupukupu, pohinahina, ilieʻe, ʻūlei, kuluʻi, lonomea, and manele.

It's important to note that ʻaʻaliʻi, like many native Hawaiian plants, may behave differently in cultivation than in its natural habitat. Environmental factors, such as strong winds, can impact the plant's growth and appearance. So, while a collected seed may come from a low-growing or prostrate plant, its growth rate and maturity in your yard will depend on your location and weather, and so it may not retain the prostrate form.

Pests and Diseases

Whiteflies, scale, and spider mites can be potential threats. Recently, the introduced lobate lac scale (Paratachardina pseudolobata) has become a serious pest on ‘a‘ali‘i, capable of killing even large adult plants. If you discover this scale insect on one or two branches of your ‘a‘ali‘i, try to remove them by hand or prune and throw away the branch(es) rather than place them in a green waste recycle bin or add to the compost. However, if the infestation is widespread, the only effective treatment to date may be spraying or root drenching with a systemic insecticide like imidacloprid. Refer to the Pests & Diseases page for treatments.

Uses

Ancient Hawaiian

Early Hawaiians utilized ʻaʻliʻi for a variety of purposes. The yellowish-brown hardwood, sometimes with black heartwood, was highly valued for its strength and versatility. It was commonly used in canoe building, weapons, agricultural tools, rafters, posts, and thatching posts or purlins in house (hale) construction [Krauss 1993, Leonard 2012, Medeiros et al. 1998].

The resilience of these tough shrubs was admired by the people of Kaʻū, as evidenced by the ancient saying: "He ʻaʻaliʻi au; ʻaʻohe makani e hina ai," which translates to "I am an ʻaʻaliʻi shrub; no wind can push me over," or in other words, "I can hold my own even in the face of difficulties." This sentiment reflects the idea of standing strong in the face of adversity [Neal 1965].

In addition to its structural uses, ʻaʻliʻi was also valued for its practical applications. The seeds were boiled to create red dye for decorating kapa (tapa) cloth [Krauss 1993, Medeiros et al. 1998]. The durable wood was used for bait sticks in fishing, as it was heavy and sank in water, making it ideal for attracting fish or heʻe (octopus) [Krauss 1993, Leonard 2012].

Furthermore, ʻaʻliʻi fruits (capsules) and leaves were incorporated into lei making, showcasing the plant's versatility. The seed capsules also produced a reddish-brown dye for kapa [Mitchell 1992].

Medicinally, the crushed leaves were used topically to alleviate irritating rashes and treat contagious diseases such as ringworm or haole rot and staph infections [Leonard 2012, Medeiros et al. 1998].

The flowers of ʻaʻliʻi were utilized for their bitter flavor and tonic properties [Little 1989]. In a treatment known as holoina, ʻaʻliʻi leaves were combined with ala‘a (Planchonella sandwicensis) bark and puakala ku kula (Argemone glauca) root, then ground and strained. The resulting liquid was heated in a steam bath and followed by a purge of ground pilikai (Stictocardia tiliifolia) fruit to treat skin rash (‘ōhune or mane‘o) [Bishop Museum Plants of Hawai‘i].

Modern

Capsules and leaves continue to be utilized in making lei, just as they were by early Hawaiians. In modern times, this plant is used worldwide as a poultice or decocted for topical purposes only. It is important to note that this plant is mildly toxic, containing small amounts of cyanogenic toxins. Ingesting plant materials can lead to cyanide poisoning [Leonard 2012].

ʻAʻaliʻi wood is known for its termite resistance [Leonard 2012]. The cultivar 'Purpurea,' which boasts purple foliage, is commonly used as a shrub in the mainland USA.

The uses of this plant extend far beyond the Hawaiian Islands. The wood has been utilized by various cultures for crafting tool handles, walking sticks, and carving implements. It is also valued as firewood due to its easy igniting properties [Tam 1999]. In New Zealand, the Māori used the wood to create clubs and weapons, with the name "akeake" meaning forever and ever. The Seri people in Sonora, Mexico, use the plant for medicinal purposes. In New Guinea, the Yali highlanders use the wood for construction and firewood, while applying heated leaves as plasters for wounds. Additionally, the wood is used for construction in Southeast Asia, West Africa, and Brazil.

The diverse cultural uses of this plant are vast and varied, making it a valuable resource across different regions of the world.

Special Features and Information

General

The genus Dodonaea, a member of the Soapberry family (Sapindaceae), consists of approximately 70 species, 61 of which are found in Australia, with 59 of those being endemic. Dodonaea viscosa is the only pantropic species, found in tropical, subtropical, and warm temperate regions spanning from the United States (California, Arizona, Florida) to South America, Africa, southern Asia, Papua New Guinea, Australia, New Zealand, and various Pacific islands, including the Hawaiian Islands.

In addition to Dodonaea, other native Hawaiian Sapindaceae members include two endemic species: māhoe (Alectryon macrococcus), lonomea (Sapindus oahuensis), and the indigenous mānele (Sapindus saponaria).

ʻAʻaliʻi is highly variable, displaying a wide range of habits, leaf shapes, and capsule colors. Some botanists suggest that there are three distinct Dodonaea entities that can be identified in the Hawaiian Islands, potentially at the species level:

1. D. sandwicensis, primarily found in wet montane areas, features mostly 2-winged capsules [Degener 1932-]. This plant is endemic to the Hawaiian Islands [Joel Lau, Botanist].

2. D. viscosa (syn. D. angustifolia, D. eriocarpa, D. spatulata) is widespread and pantropic (throughout tropical regions), but in Hawaiʻi, it is commonly found in open, mesic to dry environments on all the main islands. These plants have fuzzy, turgid (swollen) 3-4-winged capsules [Degener 1932-].

3. D. stenoptera, found mainly on Molokaʻi and scattered sites on Oʻahu, has the largest capsules of the three species, with strongly inflated, 4-winged capsules and short, almost wingless wings. These plants were also recorded on Lānaʻi and West Maui [Joel Lau, Botanist].

ʻAʻaliʻi holds significant value as a primary food source for the caterpillars of the Blackburn butterfly (Udara blackburni), one of Hawaiʻi's two endemic butterfly species, and is a preferred host plant for the visually striking koa bug (Coleotichus blackburniae) [Leonard 2012].

Historically, the seeds of ʻaʻaliʻi served as a vital food source for the Hopue, or Greater koa-finch (Rhodacanthus palmeri). This vibrant honeycreeper, adorned in bright orange and green plumage, once thrived in the koa forests of Hawaii's Kona and Kaʻū districts. Sadly, this strikingly beautiful native bird is now extinct [Pratt 2005].

Remarkably, ʻaʻaliʻi is one of the few native Hawaiian species capable of withstanding fires. As a pioneer plant, its seeds have the ability to survive in burned areas, allowing the plant to regenerate and thrive once more [Leonard 2012].

Hawaiian Name

ʻAʻaliʻi kū ma kua (meaning ʻaʻaliʻi standing in back), ʻaʻaliʻi kū makani (ʻaʻaliʻi standing in the wind), and kūmakani (windbreak or wind resisting) [Hawaiian Dictionaries].

Etymology

The generic name, Dodonaea, is named after the Flemish physician and botanist Rembert Dodoens (1517-1585), who was later a professor of medicine at Leiden, The Netherlands [Gledhill 2008]. The specific epithet, viscosa, is derived from viscous or sticky [Gledhill 2008].

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