Balaustion exsertum
Balaustion exsertum is a species of flowering plant in the family Myrtaceae and is endemic to the south-west of Western Australia. It is a low-growing, often ground-hugging shrub with narrowly oblong leaves, white flowers, and 17 to 24 stamens.
Description
Balaustion exsertum is a low-growing, often ground-hugging shrub that typically grows to high and wide, the flowering branchlets with one or two flowers in leaf axils. Its leaves are widely spreading in dense clusters, mostly narrowly oblong, long and wide on a petiole long. The lower surface of the leaves is keeled near the tip, with usually one or two main rows of oil glands each side of the midvein. The flowers are in diameter on a peduncle long. Each flower is on a pedicel long, the floral tube is cone-shaped or hemispherical, long, wide, green and brownish-purple, the free part long. The sepals are egg-shaped, long, wide and reddish with a broad, pale border. The petals are white, long, with 17 to 24 stamens. Flowering occurs from in August to October.
Taxonomy
The species was first formally described in 1920 by Spencer Le Marchant Moore who gave it the name Baeckea exserta in the Journal of the Linnean Society, Botany from specimens collected by Frederick Stoward near Bruce Rock. In 2022, Barbara Lynette Rye transferred the species to Balaustion as B. exsertum, in the journal Nuytsia. The specific epithet means "protruding", referring to the exposed stamens.
Distribution and habitat
Balaustion exsertum grows in yellow sand with eucalypts, Allocasuarinas and Melaleucas, between the Kodi Kodjin Nature Reserve and south-east to Quairading and south-west to near Narembeen, in the Avon Wheatbelt and Mallee bioregions in the south-west of Western Australia.
Conservation status
Balaustion exsertum is listed as "Priority Three" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions, meaning that it is poorly known and known from only a few locations but is not under imminent threat.