Allocasuarina anfractuosa, commonly known as sinuous sheoak, is a species of flowering plant in the family Casuarinaceae and is endemic to a restricted area in the southwest of Western Australia. It is a bushy, monoecious shrub that has spreading, sinuous branchlets, the leaves reduced to scales in whorls of 11 to 15, the fruiting cones long containing winged seeds (samaras) long.
Allocasuarina anfractuosa is a bushy, monoecious shrub that typically grows to a height of up to about . Its branchlets are spreading, up to long and sinuous, the leaves reduced to erect or spreading, scale-like teeth long, arranged in whorls of 11 to 15 around the branchlets. The sections of branchlet between the leaf whorls (the "articles") are long and wide. Male flowers are arranged in head-like spikes long on the ends of branchlets, the anthers long. Female cones are covered with fine, white or dark yellowish hairs when young, and are sessile or on a peduncle up to long. Flowering has been observed in August and mature cones are more or less cylindrical, long and in diameter, the samaras dark brown and long.[1] [2]
Allocasuarina anfractuosa was first formally described in 2016 by Juliet Wege and Sarah Barrett in the journal Nuytsia from specimens collected by Barrett near the Pallinup River in 2014.[3] The specific epithet, (anfractuosa) means "sinuous", referring to the branchlets.
Sinuous sheoak grows in heath where it often forms dense stands, and is only known from a small area north-west of Boxwood Hill in the Esperance Plains bioregion of south-western Western Australia.
Allocasuarina anfractuosa is listed as "Priority One" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions, meaning that it is known from only one or a few locations that are potentially at risk.[4]