Bertya dimerostigma is a species of flowering plant in the family Euphorbiaceae and is endemic to inland southern Western Australia. It is an erect shrub with strap-like or narrowly oblong leaves, flowers borne singly in leaf axils, and oval capsules with a mottled, light brown seed.
Description.
"Bertya dimerostigma" is a monoecious or sometimes dioecious shrub that typically grows to a height of up to and has many glabrous, mostly sticky branches. Its leaves are strap-like or narrowly oblong, long and wide and sessile or on a short petiole. The upper surface of the leaves is green and glabrous, the lower surface white and densely covered with star-shaped hairs. The flowers are borne singly in leaf axils on a peduncle long. There are five or six oblong or narrowly egg-shaped bracts long and wide. Male flowers are sessile with five red egg-shaped or elliptic sepal lobes long and wide and have about 18 to 46 stamens. Female flowers are sessile, the five sepal lobes egg-shaped to broadly egg-shaped, long and wide. Female flowers usually have no petals, the ovary elliptic, and glabrous, the style about long with three spreading yellowish-green limbs long, each with two to four lobes long. Flowering has been recorded mostly between June and November, and the fruit is an oval capsule long and wide with a single elliptic or oblong, light brown seed mottled with dark brown, long and wide with a yellowish-white caruncle.
Taxonomy.
"Bertya dimerostigma" was first formally described in 1882 by Ferdinand von Mueller in his "Southern Science Record" from specimens collected near Victoria Spring by Ernest Giles. The specific epithet ("dimerostigma") means 'double stigma'.
Distribution and habitat.
This species of "Bertya" occurs in the south-west of Western Australia between Merredin, Hyden and Zanthus and is found in hummock grasslands, in mallee with a tall shrub understorey, and open woodland, growing on sands often overlaying clays.