Allocasuarina acutivalvis is a species of flowering plant in the family Casuarinaceae and is endemic to the southwest of Western Australia. It is a dioecious shrub to small tree that has erect branchlets, the leaves reduced to scales in whorls of 10 to 14, the fruiting cones long containing winged seeds (samaras) long.
Allocasuarina acutivalvis is a dioecious shrub to small tree that typically grows to a height of . The branchlets are erect, up to long, the leaves reduced to erect, scale-like teeth long, arranged in whorls of 10 to 14 around the branchlets. The sections of branchlet between the leaf whorls (the "articles") are long and wide. The flowers on male trees are arranged in spikes resembling a string of beads long, the anthers long. The female cones are covered with fine, white hairs when young, and are sessile or on a peduncle up to long. Mature cones are long and in diameter, the samaras black or dark brown and long.[1]
This species was first formally described in 1876 by the botanist Ferdinand von Mueller who gave it the name Casuarina acutivalvis in his Fragmenta Phytographiae Australiae.[2] [3] It was reclassified in 1982 into the genus Allocasuarina as A. acutivalvis by Lawrie Johnson in the Journal of the Adelaide Botanic Gardens.[4] [5] The specific epithet, (acutivalvis) means "sharply pointed lobes".[6]
In the same journal, Johnson described two subspecies of A. acutivalvis, and the names are accepted by the Australian Plant Census:
Allocasuarina acutivalvis grows in tall heath and open woodland, sometimes on rocky hillsides, and is widespread in the south-west of Western Australia from north of the Murchison River to Zanthus. Subspecies prinsepiana occurs from near Mullewa to near Merredin, surrounded by and sometimes intergrading with subsp. acutivalvis.
Both subspecies of A. acutivalvis are listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.