''Cyanothamnus rigenss'', commonly known as the stiff boronia, is a plant in the citrus

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

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

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 south-eastern

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

in Australia. It is a low, compact shrub with mostly

trifoliate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

glandular In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

leaves and white to pale pink, four-

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

led flowers in the 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, st ...

Description

''Cyanothamnus rigens'' is a compact shrub that grows to a height of with more or less hairy younger stems. The leaves are trifoliate with a petiole long. The leaflets are thick, often warty, narrow elliptic, long and wide. The flowers are white to pale pink and are arranged singly in leaf axils 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 ...

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 b ...

s are triangular to broadly egg-shaped, long, wide and hairy. The four

s are long and wide. The eight stamens alternate in length with those near the sepals slightly longer than those near the petals. The stigma is about the same width as the

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

. Flowering occurs from July to August and the fruit is a mostly glabrous capsule long and wide.

Taxonomy and naming

The stiff boronia was first formally described in 1863 by

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 ...

who gave it the name ''Boronia polygalifolia'' var. ''robusta'' and published the name in ''

Flora Australiensis ''Flora Australiensis: a description of the plants of the Australian Territory'', more commonly referred to as ''Flora Australiensis'', and also known by its standard abbreviation ''Fl. Austral.'', is a seven-volume flora of Australia published be ...

''. In 1929

Edwin Cheel Edwin Cheel (14 February 1872 – 19 September 1951) was an Australian botanist and collector. Before being appointed as a staff member of Centennial Park in 1897 he was a gardener in New South Wales and Queensland. Later he transferred to the R ...

gave it the name ''Boronia rigens'' and published the description in '' Journal and Proceedings of the Royal Society of New South Wales''. 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 nam ...

'',

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 evolut ...

and others changed the name to ''Cyanothamnus rigens'' 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 chara ...

. 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 ...

(''rigens'') possibly refers to the habit of this species compared to that of '' B. polygalifolia'' and '' B. nana''.

Distribution and habitat

''Cyanothamnus rigens'' grows in heath and forest, sometimes on stabilised dunes between

Bombala Bombala is a town in the Monaro region of south-eastern New South Wales, Australia, in Snowy Monaro Regional Council. It is approximately south of the state capital, Sydney, and south of the town of Cooma. The name derives from an Aboriginal ...

and Mt Coricudgy east of

Rylstone Rylstone is a village and civil parish in the Craven district of North Yorkshire, England. It is situated very near to Cracoe and about 6 miles south west of Grassington. The population of the civil parish as of the 2011 census was 160. Ryls ...

References

{{Taxonbar, from=Q106902274 rigens Flora of New South Wales Plants described in 1929 Taxa named by Edwin Cheel