''Cyanothamnus occidentalis'', commonly known as the rock boronia, is a plant in the citrus

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Rutaceae The Rutaceae () is a family (biology), family, commonly known as the rueRUTACEAE
in Bo ...

and is

endemic Endemism is the state of a species being found only 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 foun ...

to eastern Australia. It is an erect, woody shrub with

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

bipinnate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets ...

leaves and groups of up to three white to pale pink, pink four-

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

led flowers arranged in leaf

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

Description

''Cyanothamnus occidentalis'' is an erect, woody shrub that grows to a height of about . It has pinnate or bipinnate leaves with between three and seven leaflets. The leaf is long and wide in outlines, on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

. The end leaflet long and wide and the side leaflets are similar but longer. The flowers are white to pale pink and are arranged singly or in groups of up to three in leaf axils on a peduncle 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 Etymology The term ''sepalum'' ...

s are triangular, long and wide. The four

s are long. The eight stamens are hairy on their edges and the stigma is tiny, no wider than the

style Style, or styles may refer to: Film and television * ''Style'' (2001 film), a Hindi film starring Sharman Joshi, Riya Sen, Sahil Khan and Shilpi Mudgal * ''Style'' (2002 film), a Tamil drama film * ''Style'' (2004 film), a Burmese film * '' ...

. Flowering mainly occurs from July to January and the fruit is a capsule long and about wide with the petals remaining.

Taxonomy and naming

This species was first formally described in 2003 by

Marco F. 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 evoluti ...

who gave it the name ''Boronia occidentalis'' from a specimen collected in the Wondul Range National Park and the description was published in '' Muelleria''. In a 2013 paper in the journal ''

Taxon In biology, a taxon (back-formation from ''taxonomy''; : 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 name and ...

'',

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 evoluti ...

and others changed the name to ''Cyanothamnus occidentalis'' on the basis of

cladistic analysis Cladistics ( ; from Ancient Greek 'branch') 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 ...

. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

(''occidentalis'') is a

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word meaning "western", alluding to the fact that in most places, this species has a more westerly distribution than that of other boronias.

Distribution and habitat

The rock boronia is one of the most widespread boronias and is found between Mount Sturgeon near

Hughenden Hughenden may refer to: *Hughenden, Queensland, a town in Australia * Hughenden, Alberta, a village in central Alberta, Canada *Hughenden Valley, a village in Buckinghamshire, England *Hughenden Manor, a mansion in High Wycombe, Buckinghamshire, Eng ...

in north

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

and

Dubbo Dubbo (; ) is a city in the Orana (New South Wales), Orana Region of New South Wales, Australia. It is the largest population centre in the Orana region, with a population of 43,516 at June 2021. The city is located at the intersection of the ...

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. It mostly grows in woodland on sandstone or in sandy soil.

Conservation

''Cyanothamnus occidentalis'' (as ''Boronia occidentalis'') is listed as of "least concern" by the Queensland Government Department of Environment and Science.

References

{{Taxonbar, from=Q106902208 occidentalis Flora of New South Wales Flora of Queensland Plants described in 2003 Taxa named by Marco Duretto