Conospermum caeruleum


Conospermum caeruleum, commonly known as blue brother, is a species of flowering plant in the family Proteaceae and is endemic to the south west of Western Australia. It is a prostrate shrub with small, dense heads of blue, rarely pink flowers and usually grows in heavy soils subject to flooding.

Description

It grows as a prostrate or straggly shrub usually growing to a height of about and a spread of up to. The leaves are clustered at the base of the stem, have a stalk and a leaf blade that is thread-like to egg-shaped and. The leaves have prominent veins and end abruptly in a sharp point. The flowers are arranged in dense clusters of up to 18 tube-like blue flowers, each about long. Flowers appear between July and October and are followed by the fruit which is a nut about long and wide.

Taxonomy

Conospermum caeruleum was first formally described in 1810 by Robert Brown and the description was published in Transactions of the Linnean Society of London from a specimen collected near "King George's Sound, west coast of New Holland". The specific epithet is a Latin word meaning "sky-blue".
Six subspecies are recognised by the Australian Plant Census as at November 2020:
  • Conospermum caeruleum R.Br. subsp. caeruleum
  • Conospermum caeruleum subsp. contortum E.M.Benn.
  • Conospermum caeruleum subsp. debile E.M.Benn.
  • Conospermum caeruleum subsp. marginatum E.M.Benn.
  • Conospermum caeruleum subsp. oblanceolatum E.M.Benn.
  • Conospermum caeruleum subsp. spathulatum Benth. E.M.Benn.

Distribution and habitat

Conospermum caeruleum occurs from Busselton to east of Albany in the Avon Wheatbelt, Esperance, Geraldton Sandplains, Jarrah Forest, Mallee, Swan Coastal Plain and Warren biogeographical regions of Western Australia growing on sand, sandy peat, stony clay, laterite or granite in areas that are wet in winter.

Use in horticulture

Conospermum species, especially the Western Australian ones are difficult to cultivate.

Conservation status

Conospermum caeruleum is classified as "not threatened" by the Government of Western Australia Department of Parks and Wildlife.