Cliff Net-bush

Cliff Net-bush, Calothamnus rupestris, is a small shrub in the family Myrtaceae endemic to southwestern Western Australia, one of the world's recognized biodiversity hotspots. Calothamnus species, known as net-bushes or one-sided bottlebrushes, are characterized by their distinctive flower clusters arranged in a one-sided bottlebrush pattern along woody stems, with brush-like red staminal bundles typical of the genus. Cliff Net-bush grows on cliff faces, rocky slopes, and granite outcrops in the kwongan heathland of the Southwest Australian Floristic Region, tolerating the thin, nutrient-poor soils and periodic drought characteristic of these rocky substrates. The flowers provide nectar for native honeyeaters and insects. Like the majority of southwest Australian endemic plants, Cliff Net-bush is adapted to the ancient, nutrient-impoverished soils of the Gondwanan continent and the Mediterranean-type climate with hot, dry summers and mild, wet winters. Threats facing southwest Australian heathland endemics include habitat clearing for agriculture, dieback disease caused by the introduced pathogen Phytophthora cinnamomi, altered fire regimes, and climate change. The conservation status of Calothamnus rupestris requires monitoring given the overall pressure on southwest Australian flora.