''Swainsona rotunda'' is a species of flowering plant in the family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

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 inland areas of northern Western Australia. It is a prostrate

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

with

imparipinnate 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 in ...

leaves with about 7 narrowly lance-shaped leaflets, and

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

s of up to 4

lilac ''Syringa'' is a genus of 12 currently recognized species of flowering woody plants in the olive family or Oleaceae called lilacs. These lilacs are native to woodland and scrub from southeastern Europe to eastern Asia, and widely and commonly ...

-coloured flowers.

Description

''Swainsona rotunda'' is prostrate herb with imparipinnate leaves up to long with about 7 narrowly lance-shaped leaflets, the side leaflets mostly long and mostly about wide. There is a

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole (botany), petiole). They are primarily found among dicots and rare among monocots. Stipules are considered part ...

long at the base of the petiole. The flowers are arranged in racemes long with about 7 flowers on a peduncle less than wide, each flower about long 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

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 joined at the base, forming a tube about long, the sepal lobes about as long as the tube. The petals are lilac-coloured, the

standard Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object ...

petal about long and wide, the

wings A wing is a type of fin that produces both lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform. Wing efficiency is expressed as lift-to-drag ratio, which compares the bene ...

about long, and the

keel The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often ...

about long and deep. Flowering has been observed in August, and the fruit is more or less round, about long and wide.

Taxonomy and naming

''Swainsona rotunda'' was first formally described in 1993 by

Joy Thompson Joy Thompson (born Joy Gardiner-Garden, 1923, died 2018) was an Australian botanist. Her main research areas were taxonomy and Myrtaceae. Life and career Thompson's university studies occurred during the second world war and in university vacat ...

in the journal '' Telopea'' from specimens in 1975. 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 ...

(''rotunda'') means "round", referring to the shape of the fruit.

Distribution and habitat

This species of pea grows in red, sandy loam in the

Gascoyne The Gascoyne region is one of the nine regions of Western Australia. It is located in the northwest of Western Australia, and consists of the local government areas of Carnarvon, Exmouth, Shark Bay and Upper Gascoyne. The Gascoyne has about of ...

and Murchison bioregions of northern inland Western Australia.

References

{{Taxonbar, from=Q51045875

rotunda A rotunda () is any roofed building with a circular ground plan, and sometimes covered by a dome. It may also refer to a round room within a building (an example being the one below the dome of the United States Capitol in Washington, D.C.). ...

Fabales of Australia Flora of Western Australia Taxa named by Joy Thompson Plants described in 1993