Pentaceras



Pentaceras australe, commonly known as bastard crow's ash, penta ash or black teak, 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.

Description
Pentaceras australe is a tree that typically grows to a height of 27 m with a dbh of 45 cm. The bark is smooth and grey fawn with small horizontal lines, flanged at the base of larger trees. The leaves are pinnate, 150–500 mm long with five to fifteen leaflets. The leaflets are egg-shaped to lance-shaped, 50–130 mm long and 7–65 mm wide, the side leaflets sessile or on a petiolule up to 9 mm long, the end leaflet on a petiolule 7–35 mm long. The flowers are about 6 mm in diameter and are borne in perfumed panicles 120–350 mm long, the sepals 0.6–1 mm long and the petals white, 2.5–3 mm long. Flowering occurs from June to October and the fruit is a samara 20–45 mm long, the seed about 3 mm long.

Taxonomy
The genus Pentaceras was first formally described in 1862 by George Bentham and Joseph Dalton Hooker in Genera Plantarum. In 1863, Ferdinand von Mueller described Cookia australis in Fragmenta phytographiae Australiae and in 1863, Bentham changed the name to Pentaceras australe in Flora Australiensis.

Distribution and habitat
Pentaceras australe grows in rainforest, often dry rainforest, from near sea level to an altitude of 900 m and occurs from near Gympie in Queensland to near Stroud in New South Wales.

Conservation status
Bastard crow's ash is classified as of "least concern" under the Queensland Government Nature Conservation Act 1992.