''Calothamnus'' is a genus of flowering plants in the family

Myrtaceae Myrtaceae (), the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All ...

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 the south-west of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. The common names one-sided bottlebrush or claw flower are given to some species due to their having the flowers clustered on one side of the stem or because of the claw-like appearance of their flowers. ''Calothamnus'' species are generally medium to tall woody shrubs with crowded leaves. In most species the leaves are crowded and linear in shape, and the flowers are usually arranged in dense clusters. The

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 ...

s are small and fall off the flower soon after it opens but the stamens are long, numerous and usually bright red.

Description

Plants in the genus ''Calothamnus'' are medium to tall shrubs, sometimes low-growing ground covers. The leaves are linear or narrow lance-shaped with the narrower end towards the base, usually

glabrous Glabrousness () 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 a plant or animal, or be due to loss because of a physical condition, ...

and have distinct oil glands. The flowers are in small groups or dense spikes on leafless, older stems or between the leaves on younger ones. 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 fused to form a bell-shaped cup which is often immersed in the branch and there are four or five

s which usually fall off after the flower has opened. There are many stamens, joined for a large proportion of their length into four or five "claws". In some species the upper two claws are fused together and the lower ones are shorter. The stamens are brightly coloured, crimson to a deep purple or rarely yellow. The fruit is a woody capsule. Calothamnus graniticus subsp

Taxonomy and naming

The first species in the genus to be described was '' Calothamnus sanguineus''. It was first formally described in 1806 by the French biologist

Jacques Labillardière Jacques-Julien Houtou de Labillardière (28 October 1755 – 8 January 1834) was a French biologist noted for his descriptions of the flora of Australia. Labillardière was a member of a voyage in search of the Jean-François de Galaup, comte ...

in '' Novae Hollandiae Plantarum Specimen, Volume 2''. The name ''Calothamnus'' is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

words ''kalos'' meaning "beautiful" and ''thamnos'' meaning "a shrub" or "a bush". In 2014,

Lyndley Craven Lyndley Alan Craven (3 September 1945 – 11 July 2014) was a botanist who became the Principal Research Scientist of the Australian National Herbarium. Lyndley ("Lyn") Craven worked for the Commonwealth Scientific and Industrial Research Organ ...

and others proposed, mainly on the basis of DNA evidence, that species in the genus ''Calothamnus'', along with those in '' Beaufortia'', '' Conothamnus'', '' Eremaea'', '' Lamarchea'', '' Petraeomyrtus'', '' Phymatocarpus'' and ''

Regelia ''Regelia'' is a genus of flowering plants in the family Myrtaceae and is endemic (ecology), endemic to the Southwest_Australia, south-west of Western Australia. The genus is composed of five species of small leaved, evergreen shrubs which hav ...

'' be transferred to ''

Melaleuca ''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles, bottlebrushes or tea-trees (although the last name is also applied to species of '' Leptospermum''). They ...

''.

Distribution and habitat

All ''Calothamnus'' species are found in the south west botanical province of Western Australia. Some (such as '' Calothamnus aridus'') are adapted to a dry environment whilst others (such as '' Calothamnus hirsutus'') are often found near swamps.

Use in horticulture

Most species of ''Calothamnus'' have been grown in gardens but need full sun and good drainage. Propagation is usually from seeds which are retained in the hard fruits throughout the life of the plant but cuttings can be used to retain the colour of yellow forms.

Species list

The following is a list of species accepted by the

Australian Plant Census The Australian Plant Census (APC) provides an online interface to currently accepted, published, scientific names of the vascular flora of Australia, as one of the output interfaces of the national government Integrated Biodiversity Information Sys ...

as at June 2025: *'' Calothamnus accedens'' Hawkeswood *'' Calothamnus affinis'' Turcz. *'' Calothamnus arcuatus'' A.S.George *'' Calothamnus aridus'' Hawkeswood *'' Calothamnus blepharospermus''

F.Muell. Baron Sir Ferdinand Jacob Heinrich von Mueller, (; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Victoria (state), Vic ...

*'' Calothamnus borealis'' Hawkeswood *'' Calothamnus brevifolius'' Hawkeswood *'' Calothamnus chrysanthereus'' F.Muell. - claw flower *'' Calothamnus cupularis'' A.S.George *'' Calothamnus formosus'' Hawkeswood *'' Calothamnus gibbosus''

Benth. 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 studie ...

*'' Calothamnus gilesii'' F.Muell. *'' Calothamnus glaber'' (Benth.) A.S.George *'' Calothamnus gracilis'' R.Br. *'' Calothamnus graniticus'' Hawkeswood *'' Calothamnus hirsutus'' Hawkeswood *'' Calothamnus huegelii'' Schauer *'' Calothamnus lateralis'' Lindl. *'' Calothamnus lehmannii'' Schauer *'' Calothamnus longissimus'' F.Muell. *'' Calothamnus macrocarpus'' Hawkeswood *'' Calothamnus microcarpus'' F.Muell. *'' Calothamnus montanus'' A.S.George *'' Calothamnus oldfieldii'' F.Muell. *'' Calothamnus pachystachyus'' Benth. *'' Calothamnus phellosus'' A.S.George *'' Calothamnus pinifolius'' F.Muell. - dense claw-flower *'' Calothamnus planifolius'' Lehm. *'' Calothamnus preissii'' Schauer *''

Calothamnus quadrifidus ''Calothamnus quadrifidus'', commonly known as one-sided bottlebrush, is a plant in the myrtle family, Myrtaceae and is endemic to the south-west of Western Australia. The common name alludes to the arrangement of the flowers in the infloresce ...

'' R.Br. - one-sided bottlebrush *'' Calothamnus robustus'' Schauer *'' Calothamnus roseus'' A.S.George *'' Calothamnus rupestris'' Schauer - mouse ears *'' Calothamnus sanguineus'' Labill. - silky-leaved blood-flower *'' Calothamnus scabridus'' A.S.George *'' Calothamnus schaueri'' Lehm. *'' Calothamnus superbus'' Hawkeswood & Mollemans *'' Calothamnus torulosus'' Schauer *'' Calothamnus tuberosus'' Hawkeswood *'' Calothamnus validus'' S.Moore - Barrens claw-flower *'' Calothamnus villosus'' R.Br.

References

{{Taxonbar, from=Q2713870 Myrtaceae genera Myrtales of Australia Rosids of Western Australia Taxa named by Jacques Labillardière Endemic flora of Southwest Australia