''Regelia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

s 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 spe ...

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 els ...

to the south-west of

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to ...

. The genus is composed of five

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of small leaved,

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

shrubs which have heads of flowers on the ends of branches which continue to grow after flowering. Another species, previously known as ''Regelia punicea'' and which is endemic to

Kakadu National Park Kakadu National Park is a protected area in the Northern Territory of Australia, southeast of Darwin. It is a World Heritage Site. Kakadu is also gazetted as a locality, covering the same area as the national park, with 313 people recorded l ...

in the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Au ...

, has been transferred to '' Melaleuca punicea''.

Description

Plants in the genus ''Regelia'' are woody, evergreen shrubs ranging in height from . Their leaves are small, arranged in opposite pairs or spirally and are noted for bearing essential oils. Their flowers are pinkish purple, rarely red, and are arranged in heads on the ends of branches which continue to grow after flowering. The flowers have 5

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 ...

s, 5

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

s and numerous

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

s arranged in 5 bundles around the edge of the flower. In many respects, they are similar to plants in the

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...

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

'', ''

Calothamnus ''Calothamnus'' is a genus of shrubs in the family Myrtaceae and is endemic to the south-west of Western Australia. The common names one-sided bottlebrush or claw flower are given to some species due to their having the flowers clustered o ...

'', ''

Conothamnus ''Conothamnus'' is a genus of flowering plants in the family Myrtaceae and is endemic to the south-west of Western Australia. They are woody shrubs similar to melaleucas but differ in that their leaves are usually arranged in opposite pairs and ...

'' and '' Phymatocarpus'' but differ from them either in the attachment of the anthers to their stalks, the way they open to release

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...

, or the number of seeds in the fruits. Plants in the genus ''Regelia'' have their anthers attached at the base (rather than the side) and open at terminal pores (rather than slits). The fruits are woody capsules with three

valves A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

and have a maximum of two fertile seeds in each valve.

Taxonomy and naming

The genus ''Regelia'' was first formally described in 1843 by J.C.Schauer in the journal ''Linnaea; Ein Journal für die Botanik in ihrem ganzen Umfange'' and the first species he named was '' Regelia ciliata''. The name ''Regelia'' honours

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

gardener and botanist

Eduard August von Regel Eduard August von Regel (sometimes Edward von Regel or Edward de Regel or Édouard von Regel), Russian: Эдуард Август Фон Регель; (born 13 August 1815 in Gotha; died 15 April 1892 in St. Petersburg) was a German horticultura ...

Distribution and habitat

All five ''Regelia'' species are found in the

South West Botanical Province Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Aus ...

. They grow in sand or sandy soil, often on the margins of winter-wet depressions.

Conservation

Two species, '' Regelia cymbifolia'' and '' Regelia megacephala'', are classified as "Priority Four" by the Western Australian government Department of Parks and Wildlife meaning that they are rare or near threatened.

Species

There are currently five recognized species of ''Regelia''. A sixth species, ''Regelia punicea'' was originally formally described in 1984 by N.B.Byrnes as ''Melaleuca punicea'', renamed ''Regelia punicea'' by B.A.Barlow in 1987, then ''Petraeomyrtus punicea'' by L.A.Craven in 2010 and finally in 2013, returned to '' Melaleuca punicea'' by Craven on the basis of molecular data. * '' Regelia ciliata'' Schauer ; * '' Regelia cymbifolia'' ( Diels)

C.A.Gardner Charles Austin Gardner (6 January 1896 – 24 February 1970) was an English-born Western Australian botanist. Biography Born in Lancaster, in England, on 6 January 1896, Gardner emigrated to Western Australia with his family in 1909, whe ...

; * ''

Regelia inops ''Regelia inops'' is a plant in the myrtle family, Myrtaceae and is endemic to the south-west of Western Australia. It is an upright but often spreading shrub with tiny wedge shaped leaves and small heads of pink flowers on the ends of its bra ...

'' (Schauer) Schauer; * '' Regelia megacephala'' C.A.Gardner ; * ''

Regelia velutina ''Regelia velutina'', the Barrens regelia, is a species of flowering plant in the myrtle family Myrtaceae. It is endemic to the south-west of Western Australia. It is a large shrub with greyish green, velvety leaves and large clusters of brillian ...

'' (

Turcz. Nikolai Stepanovich Turczaninow ( ru , Николай Степанович Турчанинов, 1796 in Nikitovka, now in Krasnogvardeysky District, Belgorod Oblast, Russia – 1863 in Kharkov) was a Russian botanist and plant collector wh ...

) C.A.Gardner – Barrens regelia.

References

{{Taxonbar, from=Q2712906 Myrtaceae genera Myrtales of Australia Endemic flora of Southwest Australia