Pentaceras australe, commonly known as bastard crow's ash, penta ash or black teak,[1] is the only species in the genus Pentaceras in the plant family Rutaceae. It is a small to medium-sized rainforest tree endemic to eastern Australia. It has pinnate leaves with up to fifteen leaflets, small white flowers arranged in panicles on the ends of branchlets, and winged seeds.
Pentaceras australe is a tree that typically grows to a height of with a dbh of . The bark is smooth and grey fawn with small horizontal lines, flanged at the base of larger trees. The leaves are pinnate, long with five to fifteen leaflets. The leaflets are egg-shaped to lance-shaped, long and wide, the side leaflets sessile or on a petiolule up to long, the end leaflet on a petiolule long. The flowers are about in diameter and are borne in perfumed panicles long, the sepals long and the petals white, long. Flowering occurs from June to October and the fruit is a samara long, the seed about long.[2] [3]
The genus Pentaceras was first formally described in 1862 by George Bentham and Joseph Dalton Hooker in Genera Plantarum.[4] [5] In 1863, Ferdinand von Mueller described Cookia australis in Fragmenta phytographiae Australiae[6] [7] and in 1863, Bentham changed the name to Pentaceras australe in Flora Australiensis.[8] [9]
Pentaceras australe grows in rainforest, often dry rainforest, from near sea level to an altitude of and occurs from near Gympie in Queensland to near Stroud in New South Wales.
Bastard crow's ash is classified as of "least concern" under the Queensland Government Nature Conservation Act 1992.[10]