''Thryptomene micrantha'', commonly known as ribbed thryptomene, is a species of flowering plant in the family

Myrtaceae Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All spe ...

and is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

to south-eastern Australia. It is a spreading to erect shrub with egg-shaped leaves, the narrower end towards the base, and white flowers with five petals and five

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

Description

''Thryptomene micrantha'' is a woody, spreading to erect shrub that typically grows to a height of and has crowded leaves, egg-shaped with the narrower end towards the base, arranged in opposite pairs, each leaf long and wide on a short petiole. The flowers are arranged in upper leaf axils, singly or in groups of up to three, each flower on a

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

about long. The floral cup is cylindrical with then longitudinal ridges and the five sepals are egg-shaped, long. The five petals are white, egg-shaped, about long and there are five stamens. Flowering mainly occurs from August to October.

Taxonomy and naming

''Thryptomene micrantha'' was first formally described in 1853 by English botanist

Joseph Dalton Hooker Sir Joseph Dalton Hooker (30 June 1817 – 10 December 1911) was a British botanist and explorer in the 19th century. He was a founder of geographical botany and Charles Darwin's closest friend. For twenty years he served as director of ...

in ''

Hooker's Journal of Botany and Kew Garden Miscellany ''Hooker's Journal of Botany and Kew Garden Miscellany'' was a scientific journal In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. ...

''. His description was based on a collection made by

Ronald Campbell Gunn Ronald Campbell Gunn, FRS, (4 April 1808 – 13 March 1881) was a South African-born Australian botanist and politician. Early life Gunn was born at Cape Town, Cape Colony, (now South Africa), the son of William Gunn, lieutenant in the 72 ...

from plants growing on "banks of sand and oyster-shells" on

Schouten Island Schouten Island (formerly Schouten's Isle), part of the Schouten Island Group, is an island with an area of approximately lying close to the eastern coast of Tasmania, Australia, located south of the Freycinet Peninsula and is a part of Frey ...

off Tasmania's east coast. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''micrantha'') means "small-flowered".

Distribution and habitat

Ribbed thryptomene occurs in scattered populations in South Australia, Victoria and Tasmania, growing in heath or woodland, sometimes in shrubland on rocky slopes. In Victoria it occurs in the region of the

Gippsland Lakes The Gippsland Lakes are a network of coastal lakes, marshes and lagoons in East Gippsland, Victoria, Australia covering an overall area of about between the rural towns of Lakes Entrance, Bairnsdale and Sale. The largest of the lakes ar ...

, while in Tasmania populations are mostly confined to the

Freycinet National Park Freycinet National Park is a national park on the east coast of Tasmania, Australia, 125 km northeast of Hobart. It occupies a large part of the Freycinet Peninsula, named after French navigator Louis de Freycinet, and Schouten Island. Foun ...

. In South Australia it is found mainly on the

Eyre Eyre may refer to: Name *Eyre (given name) *Eyre (surname) Places Australia National *Eyre Highway, a highway connecting South Australia and Western Australia South Australia * Eyre Peninsula (disambiguation) *Eyre, South Australia, a suburb * ...

and Yorke peninsulas.

Conservation status

In Tasmania this species is listed as "vulnerable" under the ''

Threatened Species Protection Act 1995 The ''Threatened Species Protection Act 1995'' (TSP Act), is an act of the Parliament of Tasmania that provides the statute relating to conservation of flora and fauna. Its long title is An Act to provide for the protection and management of t ...

'', and in Victoria as "rare" on the Department of Sustainability and Environment's ''Advisory List of Rare Or Threatened Plants In Victoria''.

References

{{Taxonbar, from=Q7798628 micrantha Flora of South Australia Flora of Tasmania Flora of Victoria (state) Plants described in 1853 Taxa named by Joseph Dalton Hooker