''Thomasia macrocalyx'' is a species of flowering plant in the family

Malvaceae Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, cotton, cacao and durian. There are also some genera containing familiar ...

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 the

south-west The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...

of Western Australia. It is an erect, bushy shrub with densely hairy new growth, egg-shaped leaves with a heart-shaped base and lobed or toothed edges, and groups of pale purple to mauve or white flowers.

Description

''Thomasia macrocalyx'' is an erect, bushy shrub that typically grows to a height of , its young growth densely covered with pale or brownish, star-shaped hairs. The leaves are egg-shaped with a heart-shaped base, long and wide on a petiole long. The edges of the leaves are toothed or lobed, both surfaces densly covered with star-shaped hairs, the upper surface becoming

glabrous Glabrousness (from the Latin ''glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

with age. The flowers are arranged in hairy

raceme A raceme ( or ) or racemoid is an unbranched, 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 produced as the s ...

s of 2 to 6, long with egg-shaped

bracteoles In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

long at the base, the flowers in diameter. 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 The term ''sepalum'' was coined b ...

s are joined at the base and covered with both simple and star-shaped hairs. Flowering occurs from May to December.

Taxonomy and naming

''Thomasia macrocalyx'' was first formally described in 1845 by

Ernst Gottlieb von Steudel Ernst Gottlieb von Steudel (30 May 1783 – 12 May 1856) was a German physician and an authority on poaceae, grasses. Biography Ernst Gottlieb von Steudel was born at Esslingen am Neckar in Baden-Württemberg. He was educated at the University of ...

in Lehmann's ''

Plantae Preissianae ''Plantae preissianae sive enumeratio plantarum quas in australasia occidentali et meridionali-occidentali annis 1838-1841 collegit Ludovicus Preiss'', more commonly known as ''Plantae preissianae'', is a book written by Johann Georg Christian Leh ...

'' from specimens collected near

Preston Beach Preston is a place name, surname and given name that may refer to: Places England *Preston, Lancashire, an urban settlement **The City of Preston, Lancashire, a borough and non-metropolitan district which contains the settlement **County Boro ...

. 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 ...

(''macrocalyx'') means "large calyx", referring to the sepals.

Distribution and habitat

This thomasia grows on sandplains, hills and breakaways, often near creeks or on slopes, mainly near the

Darling Range 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 ...

in the

Avon Wheatbelt The Avon Wheatbelt is a bioregion in Western Australia. It has an area of . It is considered part of the larger Southwest Australia savanna ecoregion. Geography The Avon Wheatbelt bioregion is mostly a gently undulating landscape with low reli ...

Esperance Plains Esperance Plains, also known as Eyre Botanical District, is a biogeographic region in southern Western Australia on the south coast between the Avon Wheatbelt and Hampton bioregions, and bordered to the north by the Mallee region. It is a pl ...

Geraldton Sandplains Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

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. It is most common in the biogeographic region named in ...

, Mallee 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 geol ...

bioregions of south-western Western Australia.

Conservation status

''Thomasia macrocalyx'' is listed as "not threatened" by the Western Australian Government

Department of Biodiversity, Conservation and Attractions The Department of Biodiversity, Conservation and Attractions (DBCA) is the Western Australian government The Government of Western Australia, formally referred to as His Majesty's Government of Western Australia, is the Australian state de ...

References

{{Taxonbar, from=Q17580963 macrocalyx Rosids of Western Australia Plants described in 1845 Taxa named by Ernst Gottlieb von Steudel