Styphelia longissima is a species of flowering plant in the heath family Ericaceae and is endemic to a few places in the south-west of Western Australia. It is an erect shrub with hairy young branchlets, stem-clasping, sharply-pointed, narrowly egg-shaped to narrowly elliptic leaves, and white, tube-shaped flowers.
Styphelia longissima is an erect shrub with hairy young branchlets, that typically grows up to high and wide. Its leaves are stem-clasping, narrowly egg-shaped to narrowly elliptic, long and wide on a petiole long. The end of the leaves is sharply-pointed and the edges usually have hairs long. The flowers are arranged singly in leaf axils and are erect and sessile with egg-shaped to elliptic bracts long and bracteoles long and wide. The sepals are narrowly egg-shaped to narrowly elliptic, long and wide and straw-coloured. The petals are white and joined at the base to form a tube long and wide, with lobes that are turned back and long. Flowering occurs between May and July.[1]
Styphelia longissima was first formally described in 2017 by Michael Hislop and Caroline Puente-Lelievre in the journal Nuytsia from specimens collected north of Eneabba in 2004.[2] The specific epithet (longissima) means "very long", referring to the point on the end of the leaf, and the hairs on the edges of the leaves and ovary.[3]
This styphelia grows in heath and open, low woodland on yellow sand in a small area near Eneabba in the Avon Wheatbelt and Geraldton Sandplains bioregions of south-western Western Australia.
Styphelia longissima is listed as "Threatened Flora (Declared Rare Flora — Extant)" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.