Ristantia pachysperma
Ristantia pachysperma, commonly known as yellow penda, is a species of plants in the clove and eucalyptus family Myrtaceae. It is native to the Wet Tropics bioregion of Queensland, Australia, and is listed as critically endangered. It was first described in 1982.
Description
It is a large rainforest tree reaching up to in height, with brown furrowed bark and buttresses. The leaves are simple, arranged alternately or in whorls on the twigs, and are obovate in shape. They can grow up to long and are attached to the twig by a petiole up to long.
The inflorescences are produced from the and are about long. They carry numerous quite small flowers, each with five white petals about long. Stamens number about 100 and are arranged in groups opposite the petals, each group with up to four sterile stamens and 15–20 fertile ones.
The woody fruit is about diameter, with three locules or segments, and they usually contain one or two seeds per fruit.
Taxonomy
This species was first described in 1886 as Xanthostemon pachyspermus by botanists Ferdinand von Mueller and Frederick Manson Bailey. It was described again in 1920 by Cyril Tenison White and William Douglas Francis, who, unaware that they were dealing with the same plant as Mueller and Bailey's earlier work, gave it the combination Tristania odorata. In 1951, having realised the error, Francis published a new combination, keeping the earlier species epithet pachyspermus but placing it in the genus Tristania. By 1980, botanist Peter Gordon Wilson had recognised that Tristania contained a number of species that were not closely related, and he published a full revision of the genus in 1982, resulting in the creation of the new genus Ristantia and the transfer of this species to it.
Etymology
The name Ristantia is an anagram of Tristania.The species epithet is derived from the Ancient Greek words păkhŭ́s, thick, and spérma, seed, as a reference to the hard woody capsules.
Conservation
This species is listed as critically endangered under the Queensland Government's Nature Conservation Act., it has not been assessed by the International Union for Conservation of Nature.