''Thryptomene hexandra'', commonly known as Palm Valley myrtle in the Northern Territory, 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 speci ...

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 elsew ...

to north-eastern Australia. It is an erect, much-branched shrub with linear to lance-shaped leaves and white flowers with six

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 filame ...

Description

''Thryptomene hexandra'' is an erect, much-branched, glabrous shrub that typically grows to a height of . The leaves are

decussate Decussation is used in biological contexts to describe a crossing (due to the shape of the Roman numeral for ten, an uppercase 'X' (), ). In Latin anatomical terms, the form is used, e.g. . Similarly, the anatomical term chiasma is named aft ...

, linear to lance-shaped or narrow egg-shaped with the narrower end towards the base, long, wide and scented when crushed. The flowers are arranged singly, sometimes in pairs or threes in leaf axils near the ends of branches, on peduncles up to long, each with two linear bracteoles long. The flowers have six, more or less round white

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s and petals and six stamens. Flowering occurs in most months, but especially from June to September.

Taxonomy and naming

''Thryptomene hexandra'' was first formally described in 1944 by

Cyril Tenison White Cyril Tenison ("C.T.") White (17 August 1890 – 15 August 1950) was an Australian botanist. Early life White was born in Brisbane to Henry White, a trade broker, and Louisa ''nee'' Bailey. He attended school at South Brisbane State School, an ...

in ''

Proceedings of the Royal Society of Queensland ''Proceedings of The Royal Society of Queensland'' is a multidisciplinary scientific journal published by The Royal Society of Queensland The Royal Society of Queensland was formed in Queensland, Australia in 1884 from the Queensland Philo ...

''. 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 ...

(''hexandra'') means "six stamens".

Distribution and habitat

This thryptomene occurs in New South Wales, Queensland and the Northern Territory. It grows in woodland on stony hills north from Bourke in New South Wales and in deep, narrow gorges in the southern part of the Northern Territory.

Conservation status

This species is listed as "vulnerable " under the Australian Government '' Environment Protection and Biodiversity Conservation Act 1999'' and as "near threatened" under th
''Northern Territory Government Territory Parks and Wildlife Conservation Act 1976''
but as of "least concern" under the Queensland Government ''

Nature Conservation Act 1992 The ''Nature Conservation Act 1992'' is an act of the Parliament of Queensland, Australia, that, together with subordinate legislation, provides for the legislative protection of Queensland's threatened biota. As originally published, it prov ...

''.

References

{{Taxonbar, from=Q7798626 hexandra Flora of New South Wales Flora of Queensland Flora of the Northern Territory Plants described in 1944 Taxa named by Cyril Tenison White