Allocasuarina helmsii is a species of flowering plant in the family Casuarinaceae and is endemic to the south-western Australia. It is a dioecious shrub that erect branchlets, the leaves reduced to scales in whorls of five or six, and mature fruiting cones 15–33 mm (0.59–1.30 in) long containing winged seeds (samaras) 4–5 mm (0.16–0.20 in) long.
Description
Allocasuarina helmsii is a dioecious shrub that typically grows to a height of 1–5 m (3 ft 3 in – 16 ft 5 in). Its branchlets are erect, up to 160 mm (6.3 in) long, the leaves reduced to erect, scale-like teeth 0.5–0.7 mm (0.020–0.028 in) long, arranged in whorls of five or six around the branchlets. The sections of branchlet between the leaf whorls (the "articles") are 3–7 mm (0.12–0.28 in) long and 0.7–0.9 mm (0.028–0.035 in) wide. Male flowers are arranged in spikes 5–25 mm (0.20–0.98 in) long, the anthers 0.5–0.7 mm (0.020–0.028 in) long. Female cones are usually cylindrical, softly-hairy or rusty-hairy at first, and sessile or on a peduncle up to 4 mm (0.16 in) long. Mature cones are 15–33 mm (0.59–1.30 in) long and 8–13 mm (0.31–0.51 in) in diameter, the samaras mid-brown and 4–5 mm (0.16–0.20 in) long.[2][3][4]
^ ab"Allocasuarina helmsii". Australian Biological Resources Study, Department of Agriculture, Water and the Environment: Canberra. Retrieved 6 June 2023.
^Sharr, Francis Aubi; George, Alex (2019). Western Australian Plant Names and Their Meanings (3rd ed.). Kardinya, WA: Four Gables Press. p. 215. ISBN9780958034180.
