It occurs in tropical regions of Southeast Asia, Oceania and Polynesia. The name is derived from the Greek word meaning ‘pearl barley’.
The small flowers form terminal or axillary clusters (between the leaf and the stem) of small creamy blossoms during spring. The flowers are bisexual.
The plant has hypanthium – a floral structure consisting of bases of the sepals, petals and stamens fused together.
Alphitonia flowers have five sepals, five petals and five stamens. The ovary or gynocecium (from the Greek gyne, meaning ‘woman’, and oikos, meaning ‘house’) is inferior.
The fruits are ovoid, blackish non-fleshy capsules, with one seed per locule (from the Latin loculus, meaning ‘little place’) – the chamber within the gynocecium.
The crushed leaves foam up in water and were commonly used as soap.
There’s a more detailed profile here.
The above illustration, by Sydney Parkinson, was collected by Daniel Solander in the Society Islands in 1769.