Olearia astroloba


Olearia astroloba, commonly known as Marble daisy-bush, is a rare shrub species in the family Asteraceae. It is endemic to the state of Victoria in Australia.

Description

The species grows to 0.5 metres high and has grey-green leaves that are about 18mm long and 10 mm wide. It has "daisy" flowerheads comprising mauve ray florets and yellow disc florets. The peak flowering period in the species native range is between June and July although flowers continue to appear until March.

Taxonomy

The species was first formally described in 1989 in the journal Muelleria based on plant material collected from Marble Gully in 1988. Prior to this, it was informally known as Olearia sp. Nunniong.

Distribution and habitat

The species is restricted to Marble Gully, near Mount Tambo in East Gippsland. It grows on skeletal soils on steep north-facing slopes at an altitude of about 600 metres above sea level. Associated plant species are Allocasuarina verticillata, Eucalyptus nortonii, Pomaderris oraria subsp. calcicola, Ozothamnus adnatus and Themeda triandra.

Conservation

Olearia astroloba is listed as "vulnerable" under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and "threatened" under the Victorian Flora and Fauna Guarantee Act 1988. The total population is estimated to be 1,030 plants within a 40 hectare area. Potential threats include inappropriate fire regimes, weed invasion, grazing by stock and rabbits and mining for marble.

Cultivation

The species prefer a well-drained position in full sun or part shade. It is able to withstand drought and moderate frost. Pruning promotes new growth and increased flowering. Propagation is by cuttings or seed, though a large percentage of the latter is often non-viable.