Eremaea (plant)

''Eremaea '' is a genus of woody shrubs and small trees in the family Myrtaceae and is endemic to the south-west of Western Australia. Little study of the genus as a whole had been undertaken until Roger Hnatiuk researched ''Eremaea'' and published a paper in 1993, ''A revision of the genus Eremaea (Myrtaceae)'' in Nuytsia. The first species to be described was '' Eremaea pauciflora'' (as ''Metrosideros pauciflora'') in 1837 and by 1964, the number of species known had increased to 12. Hnatiuk recognised 16 species, 5 subspecies and a number of varieties.

Description

Plants in the genus ''Eremaea'' are shrubs or small trees with small leaves that are arranged alternately on the stem and are dotted with oil glands. The flowers have both male and female parts and are solitary or in clusters of two or three on the ends of the branches. There are 5 sepals, and 5 petals which fall off as the flower matures. There are many stamens, all longer than the petals and usually arranged in groups of five. The stamens give the flowers their colour, which may be pink, deep pink, orange or violet. The fruit is a woody capsule containing one to six small seeds.

Taxonomy and naming

The genus ''Eremaea'' was first named and formally described in 1839 by John Lindley in A Sketch of the Vegetation of the Swan River Colony in which he noted "Of this genus, which may be called ''Eremaea'' ... there are three species, of which the only pretty kind is '' E. fimbriata''." (The species now known as ''Eremaea pauciflora'' had been described earlier but given the name ''Metrosideros pauciflora''.)

The genus ''Eremaea'' is closely related to '' Melaleuca'', '' Beaufortia'' ''Regelia'' and several others, differing mainly in the way the anthers are attached to the stalks of the stamens, and in the way they open to release their pollen. ''Eremaea'' is most closely related to ''Regelia'' and ''Calothamnus'' as these groups have anthers that open by longitudinal slits or pores. ''Eremaea'' can be distinguished from ''Regelia'' by the number of flowers in the flowering heads - in ''Regelia'' the flowers are in dense heads, whereas in ''Eremaea'' they are solitary or in groups of two or three. ''Calothamnus'' species have longer leaves than both of these genera. In 2014, Lyndley Craven and others proposed, mainly on the basis of DNA evidence, that species in the genus ''Eremaea'', along with those in '' Beaufortia'', '' Conothamnus'', ''Calothamnus'', '' Lamarchea'', ''Petraeomyrtus'', '' Phymatocarpus'' and ''Regelia'' be transferred to '' Melaleuca''.

The name ''Eremaea'' is from a poetic Greek word ''eremaios'' meaning "solitary", referring to the few-flowered inflorescences on the ends of the branches.

Distribution and habitat

Fifteen of the sixteen species of ''Eremaea'' occur only in the South West Botanical Province of Western Australia.Govaerts, R., Sobral, N., Ashton, P., Barrie, F., Holst, B.K., Landrum, L.L., Matsumoto, K., Fernanda Mazine, F., Nic Lughadha, E., Proença, C. & al. (2008). World Checklist of Myrtaceae: 1-455. Kew Publishing, Royal Botanic Gardens, Kew. ('' Eremaea pauciflora'' also occurs in the Eremaean province.) They are a significant part of the shrub layer in these areas.

Ecology

Species in the genus ''Eremaea'' can recover from fire by reseeding when the plant is killed and the fruits open and release their seeds. Some species also form a lignotuber so that well-established plants can resprout after fire.

Conservation

Some species of ''Eremaea'' are common within their range but several, including '' Eremaea violacea'' subsp. Dobaderry Swamp, are listed as "Priority One" by the Western Australian Government Department of Parks and Wildlife meaning that they are known from only one or a few locations which are potentially at risk. No species has been declared rare.

Use in cultivation

Some species of ''Eremaea'' have been grown in cultivation but with varying success. '' Eremaea beaufortioides'' has grown well in sunny situations with excellent drainage producing a vigorous, spreading shrub. Grafting onto ''Kunzea ambigua'' has been successful. Some other species grow well in Kings Park but are rarely seen in the eastern states. Their orange colour, not common in Australian natives, and their habit of having flowers on the ends of their branches make them worthy garden subjects.

Species list

The following is a list of the species of ''Eremaea'' as described by Roger Hnatiuk and recognised by the Western Australian Herbarium:

* '' Eremaea acutifolia'' F.Muell. – rusty eremaea
* '' Eremaea asterocarpa'' Hnatiuk
* '' Eremaea atala'' Hnatiuk
* '' Eremaea beaufortioides'' Benth.
* '' Eremaea blackwelliana'' Hnatiuk
* '' Eremaea brevifolia'' (Benth.) Domin
* '' Eremaea × codonocarpa'' Hnatiuk
* '' Eremaea dendroidea'' Hnatiuk
* '' Eremaea ebracteata'' F.Muell.
* '' Eremaea ectadioclada'' Hnatiuk
* '' Eremaea fimbriata'' Lindl.
* '' Eremaea hadra'' Hnatiuk
* '' Eremaea pauciflora'' ( Endl.) Druce
* '' Eremaea × phoenicea'' Hnatiuk
* '' Eremaea purpurea'' C.A.Gardner
* '' Eremaea violacea'' F.Muell. – violet eremaea

References

{{DEFAULTSORT:Eremaea (Plant)

Myrtaceae genera
Myrtales of Australia
Rosids of Western Australia
Endemic flora of Southwest Australia