''Cyanothamnus tenuis'', commonly known as blue boronia, is a species of plant in the citrus

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Rutaceae The Rutaceae is a family, commonly known as the rueRUTACEAE
in BoDD – Botanical Der ...

, 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 the southwest of

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to ...

. It is a slender shrub with thread-like, sessile leaves, and flowers with four petals that are white to pink on the front and pale blue on the back.

Description

''Cyanothamnus tenuis'' is a slender, woody shrub that grows to a height of . The leaves are sessile, thread-like, long with a channel along the upper surface. The flowers are borne singly or in groups of two or three in leaf

axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ...

s on a thin pedicel long. The four

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 ...

s are narrow triangular or narrow egg-shaped and about long. The petals are white to pink but pale blue on the back with a darker midline, long. Flowering occurs from August to December.

Taxonomy and naming

''Cyanothamnus tenuis'' was first formally described in 1839 by

John Lindley John Lindley FRS (5 February 1799 – 1 November 1865) was an English botanist, gardener and orchidologist. Early years Born in Catton, near Norwich, England, John Lindley was one of four children of George and Mary Lindley. George Lindley ...

in ''

A Sketch of the Vegetation of the Swan River Colony "A Sketch of the Vegetation of the Swan River Colony", also known by its standard botanical abbreviation ''Sketch Veg. Swan R.'', is an 1839 article by John Lindley on the flora of the Swan River Colony. Nearly 300 new species were published in it, ...

''. In 1863,

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studi ...

changed the name to ''Boronia tenuis'', but in a 2013 paper in the journal ''

Taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

'',

Marco Duretto Marco Duretto (born 1964) is a manager and senior research scientist at the Royal Botanic Gardens Sydney in Australia. His primary research interests are systematics and conservation of Rutaceae, Rubiaceae, Orchidaceae, Stylidiaceae and evo ...

and others changed the name back to ''C. tenuis'' on the basis of

cladistic analysis Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived ch ...

. 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 ...

(''tenuis'') is a

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

word meaning "thin".

Distribution and habitat

This species grows on laterite and granite in stony soils. It is found on the

Darling Scarp The Darling Scarp, also referred to as the Darling Range or Darling Ranges, is a low escarpment running north–south to the east of the Swan Coastal Plain and Perth, Western Australia. The escarpment extends generally north of Bindoon, to th ...

between Dwellingup and Wannamal in the

Jarrah Forest Jarrah forest is tall open forest in which the dominant overstory tree is '' Eucalyptus marginata'' (jarrah). The ecosystem occurs only in the Southwest Botanical Province of Western Australia Western Australia (commonly abbreviated as WA) is ...

and

Swan Coastal Plain The Swan Coastal Plain in Western Australia is the geographic feature which contains the Swan River as it travels west to the Indian Ocean. The coastal plain continues well beyond the boundaries of the Swan River and its tributaries, as a geo ...

biogeographic regions A biogeographic realm or ecozone is the broadest biogeographic division of Earth's land surface, based on distributional patterns of terrestrial organisms. They are subdivided into bioregions, which are further subdivided into ecoregions. De ...

Conservation status

''Cyanothamnus tenuis'' is classed as is classified as " Priority Four" by the Government of Western Australia

Department of Parks and Wildlife The Department of Parks and Wildlife (DPaW) was the department of the Government of Western Australia responsible for managing lands described in the ''Conservation and Land Management Act 1984'' and implementing the state's conservation and en ...

, meaning that is rare or near threatened.

References

{{Taxonbar, from=Q65935564 tenuis Flora of Western Australia Plants described in 1839 Taxa named by John Lindley