Neleau produces large inflorescences with many tiny yellow flowers (photograph courtesy of Forest & Kim Starr CC BY 3.0 US). When pollinated, each of these flowers develops into a fleshy drupe (photograph courtesy of Forest & Kim Starr CC BY 3.0). Neleau has large pinnately compound leaves that are a striking red when young (red leaf photograph courtesy of Forest & Kim Starr CC BY 3.0). Neleau is deciduous with its old leaves normally turning yellow to red and dropping sometime around the new year (photograph courtesy of Forest & Kim Starr CC BY 3.0). The attractive multi-colored stems of neleau are flexible but will break if bent too far (photograph courtesy of Daniel Barthelemy CC BY-SA 4.0).

A flowering neleau can be quite impressive (photograph courtesy of J.B. Friday ©) but can also attract a lot of bees. Because of its spreading nature, neleau is being planted on Hawai‘i Island where ‘ōhi‘a (Metrosideros polymorpha) have died because of the fungal disease Rapid ‘Ōhi‘a Death in an attempt to prevent alien plants from invading and taking over these former native forests (photograph courtesy of J.B. Friday ©). Left on its own, neleau tends to spread via root suckers and form a thicket (photograph courtesy of Daniel Barthelemy CC BY-SA 4.0). However, with regular and proper pruning, it's possible to turn neleau into a proper shade tree (photograph coutesy of Forest & Kim Starr CC BY 2.0).

Growth Requirements

General

    I (Koebele) am not sure why we so rarely see neleau in cultivation. Perhaps it’s misinformation from mainlanders who see neleau as a sumac and wrongly assume it must be poisonous. Well, it’s not! In fact, it’s harmless, and, although I’ve never eaten neleau fruits myself (and you too should always be cautious), they are reported to be edible [Little & Skolmen 1989]. Another possibility for neleau’s rarity in cultivation is its habit of producing numerous suckers from its roots and invasively spreading into areas of a landscape where it’s unwanted. While this is true, introduced plants like heliconias and gingers that also aggressively spread are extremely popular garden plants in Hawai‘i. Nor is neleau’s invasive spread inevitable. As you can see in the photograph above, it’s entirely possible to control the spread of neleau with regular pruning, so much so that you can actually turn your neleau into a shade tree. 

    Neleau does best in rainy places. And, while it’s possible to grow neleau in a dry-climate landscape with enough watering, it generally struggles in hot, dry places. The few times I have tried to grow neleau on the leeward side of O‘ahu, the plants consistently ended up with leaves that would brown and die along their margins; not an attractive look. Conversely, in cooler and rainier places like Hoʻomaluhia Botanical Garden on the windward side of Oahu, neleau grows like a weed [Honolulu Botanical Gardens].

Accent

Screening

Plants produce numerous root suckers and can become troublesome if planted near planting beds or areas where it is not welcomed.

Does well as a hedge or as a screen from roads.

Neleau can form dense stands and may require pruning to control. The root suckers can come up in unwanted areas.

Moist

Neleau can be grown in dry to wet conditions.

Soil must be well drained

Full sun

Partial sun

Pests and Diseases

Ants can be a nuisance. Weeds at base of plants should be controlled. historical reports of a fungus killing plants check degener rock

. Refer to the Pests & Diseases page for ways to deal with these pests.

Special Features and Information

General

    Anacardiaceae contains about 870 species of trees, shrubs, and vines within about 80 genera, with most species native to tropical and subtropical regions of the Old and New Worlds. Several species are economically important nut and fruit crops, such as pistachio (Pistacia vera), cashew (Anacardium occidentale) and the locally popular mango (Magifera indica). Not so popular and found outside Hawai‘i are poison ivy, poison oak, and poison sumac, all plants in the genus Toxicodendron [Britannica].

    The endemic neleau is the only native member of Anacardiaceae in the Hawaiian Islands. Unlike some of its non-Hawaiian cousin species (e.g., poison sumac, native to North America), neleau is not poisonous and its fruits are reportedly even edible [Little & Skolmen 1989] although I (Koebele) cannot comment on their flavor. In Hawai‘i, the introduced, naturalized, and highly invasive Christmas berry (Schinus terebinthifolia) is also a member of this family [Flora of the Hawaiian Islands].

Hawaiian Name

Etymology

    Rhus is from an ancient Greek name for a sumach [Gledhill 2008]. The species name, sandwicensis, refers to the "Sandwich Islands," as the Hawaiian Islands were once called and named by James Cook on one of his voyages in the 1770s. James Cook named the islands to honor John Montagu (The fourth Earl of Sandwich) for supporting Cook's voyages [Gledhill 2008].