Van-royena
Van-royena is a monotypic genus in the plant family Sapotaceae. The sole species is Van-royena castanosperma, commonly known as milky plum, yellow plum, saffron boxwood or poison plum, which is endemic to Queensland, Australia. It is an understorey tree of rainforest, first described in 1919.
Description
Van-royena castanosperma is an evergreen shrub or small tree up to tall. The twigs are lenticellate and glabrous, except for new growth which is finely hairy. The leaves are simple and arranged spirally on the twigs. They measure up to long by wide, and may be oblanceolate, lanceolate or elliptic. The petiole is about long and produces a milky exudate when broken. They have up to 13 pairs of lateral veins either side of the midrib.The inflorescence is a small fascicle. The flowers have 5 overlapping sepals about long, which have fine rusty brown hairs on both sides. The corolla tube is about long, with 5 broadly ovate lobes about long. The corolla is glabrous except for some fine hairs on the margins of the lobes. Stamens are attached low in the corolla tube — the filaments are about long, the anther about. The ovary is about long and diameter with 5 locules, and is densely hairy. The style is about long.
The fruit is a drupe, blue/black when ripe, with the calyx persisting at the base and an extended point at the apex. They measure up to long and wide, and they contain 1–3 seeds up to long and wide.
Taxonomy
This plant was first described as Chrysophyllum castanospermum in 1919 by Australian botanist Cyril Tenison White, based on a specimen he collected in the upper parts of the Johnstone River. The specimen had fruit but no flowers, so he was only able to describe some aspects of the flower interpreted from the fruit, stating "Corolla not seen". He was aware that his placement of the specimen in Chrysophyllum may have to be changed when "perfect flowers are available". In 1923, he and fellow Australian botanist William Douglas Francis published a new description after examining flowering specimens from the Atherton Tableland collected by G. Curry, and they transferred it to the genus Lucuma, giving it the new combination L. castanosperma.The species was renamed again in 1942, when Swiss botanist Charles Baehni published a paper in the journal Candollea in which he gave it the new binomial Pouteria castanosperma.
Most recently, in 1963, French botanist André Aubréville created the new genus Van-royena for the plant, implying some unique characteristics of the species. This move is supported by later research, and it has been suggested that the species may be the result of intergeneric cross-pollination.