Erythrina sandwicensis aka Wili Wili

Erythrina sandwicensis belongs to the pea family, Fabaceae. It is a deciduous tree: it sheds its leaves. People call it wiliwili or Hawaiian coral tree. It is native to the Hawaiian Islands. There, it grows in lowlands on the islands' leeward sides. It grows in hot, dry foothills and dry forest. It occurs below about 2,000 feet [610 metres]. People grow the tree and gather materials from wild trees.

Garden sources list its height and spread as 33 feet [10 metres]. The broader height range is 16–49 feet [5–15 metres]. Its open crown can spread wider than its height. The short, thick trunk may twist or grow gnarled. It can bear many spines. Trunks range from about 1–3 feet [0.3–0.9 metres] wide. Trees in sheltered sites can grow upright. Strong winds shape trees on exposed sites. The tree grows fast.

The species includes a form that has white flowers. Both birds and insects visit and pollinate the flowers. Flowers can set seed with their own pollen. Seedpods split open and show the bright red seeds. People use these seeds to make leis. The sources give no clear season for the blooms. They give few facts about leaf shape or flower structure.

Grow this tree in full sun, in soil that drains well. It does not suit shade. It accepts sand, loam, and clay soils. The soil can range from mildly acid to mildly alkaline. It can grow in dry or moist ground. Once it takes root in suitable conditions, it withstands long droughts. It also copes with exposed coasts and strong winds. PFAF lists USDA hardiness zones 10–12. Its native sites get about 20–49 inches of rain each year.

Wiliwili can serve as a specimen tree or living fence. Live stems planted for fences take root with ease. It fixes nitrogen, which helps in planting projects on eroded land. It can shade crops, block wind, and act as living supports. People have used its light wood for fishing-net floats and surfboards. Its charcoal adds color to paint mixes. Traditional medicine uses its flowers and bark. This does not mean those uses are safe. PFAF lists no known food uses. Useful Tropical Plants urges care with eating this tree's parts. The levels of alkaloids in this species remain unknown.