Family: Elaeocarpaceae
Elaeocarpus angustifolius, in the family Elaeocarpaceae, is a tall evergreen commonly known as the blue marble tree, blue quandong, or silver/blue quandong (Elaeocarpus grandis; E. sphaericus). Native from India and Southeast Asia through Melanesia to northern Australia and New Caledonia, this species can reach 30–40 m tall and often develops buttressed trunks with an open, dome-shaped crown. The dark green, elliptic to oblong leaves (8–15 cm long) have scalloped margins and often turn bright red before falling. In spring, the tree produces racemes of creamy-white, fringed, five-petaled flowers, followed by striking, bright blue, spherical drupes about 1 cm in diameter. In Hawai‘i, it is reported to be naturalized on O‘ahu and Hawai‘i Island, but it has not been reported to cause negative impacts to date.
The species has a long history of cultivation in Hawai‘i. Blue marble trees were planted in public landscapes as early as 1917, when a specimen was grown at the Government Nursery on King Street in Honolulu. Today, it is most often found in spacious sites such as parks, school grounds, and botanical gardens, where its high, open crown provides filtered shade. The vivid blue fruits are valued for ornamental and cultural uses—dried seeds are polished and strung into jewelry or leis, similar to the rudraksha prayer beads made throughout its native range. The tree thrives in wet windward areas and along streambanks, requiring little maintenance once established, and is easily propagated from seed despite slow germination.
High Risk Traits:
- Thrives and can spread in regions with tropical climates
- Naturalized on O‘ahu and Hawai‘i Island (Hawaiian Islands) and Samoa
- Invading intact and secondary forests in Samoa (impacts unspecified)
- Shade tolerant
- Reproduces by seed
- Seeds dispersed by water, birds, other frugivorous animals, and through intentional cultivation
- Seeds may form a persistent seed bank (>12 months)
Low Risk Traits:
- Negative impacts have not been documented where cultivated or naturalized
- Unarmed (no spines, thorns, or burrs)
- Palatable to browsing animals
- Not reported to be toxic
- Reaches maturity in 5+ years
