Olearia

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Olearia
Olearia stuartii.jpg
Olearia stuartii in Geelong Botanic Gardens
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Subfamily: Asteroideae
Tribe: Astereae
Subtribe: Brachyscominae
Genus: Olearia
Moench [1]
Type species
Olearia tomentosa
Species

See text

Olearia, most commonly known as daisy-bush, [2] is a genus of flowering plants belonging to the family Asteraceae, the largest of the flowering plant families in the world. Olearia are found in Australia, New Guinea and New Zealand. The genus includes herbaceous plants, shrubs and small trees. The latter are unusual among the Asteraceae and are called tree daisies in New Zealand. All bear the familiar daisy-like composite flowerheads in white, pink, mauve or purple.

Contents

Description

Plants in the genus Olearia are shrubs of varying sizes, characterised by a composite flower head arrangement with single-row ray florets enclosed by small overlapping bracts arranged in rows. The flower petals are more or less equal in length. The centre of the bi-sexual floret is disc shaped and may be white, yellowish or purplish, generally with 5 lobes. Flower heads may be single or clusters in leaf axils or at the apex of branchlets. Leaves may be smooth, glandular or with a sticky secretion. The leaves may grow opposite, alternate, arranged sparsely or clustered. Leaf margins either entire or lobed, with or without a stalk. The fruit are dry slightly compressed, one-seeded, narrow-elliptic or egg-shaped with longitudinal ridges and smooth or with sparse hairs. [3] [4] [5]

Taxonomy and naming

The genus Olearia was first described in 1802 by Conrad Moench in Supplementum ad Methodum Plantas and is named after Johann Gottfried Olearius, a 17th-century German scholar and author of Specimen Florae Hallensis. [6] [7] Originally a large genus, a molecular study has found it to be polyphyletic. [8]

Distribution

There are approximately 180 species of Olearia, of which about 112 species are endemic to Australia. Olearia are found in all states of Australia. [5]

Species

Olearia archeri Olearia archeri.jpg
Olearia archeri
Olearia cordata Olearia cordata.jpg
Olearia cordata
Olearia erubescens Olearia erubescens.jpg
Olearia erubescens
Olearia minor Olearia minor.jpg
Olearia minor
Olearia oporina Olearia oporina.jpg
Olearia oporina
Olearia suffruticosa Olearia suffruticosa.jpg
Olearia suffruticosa
Olearia tomentosa Olearia tomentosa.jpg
Olearia tomentosa

The following is a list of Olearia species accepted by the Australian Plant Census or the New Zealand Plant Conservation Network or listed in the Census of Vascular Plants of Papua New Guinea as at May 2021: [9] [10] [11]

Use in horticulture

Several species are cultivated as ornamental garden plants, and there are hybrids of uncertain or mixed parentage. Among these, the following have been given the Royal Horticultural Society’s Award of Garden Merit:- [12]

They are generally hardy down to −10 °C (14 °F), but require a sheltered spot in full sun.

Related Research Articles

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<i>Prostanthera</i> Genus of plants

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<i>Epacris</i> Genus of flowering plants in the heath family Ericaceae

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<i>Pimelea</i> Genus of flowering plants

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<i>Pomaderris</i> Family of shrubs and trees

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<i>Cassinia</i> Genus of flowering plants

Cassinia is a genus of about fifty-two species of flowering plants in the family Asteraceae that are native to Australia and New Zealand. Plants in the genus Cassinia are shrubs, sometimes small trees with leaves arranged alternately, and heads of white, cream-coloured, yellow or pinkish flowers surrounded by several rows of bracts.

<i>Podolepis</i> Genus of plants

Podolepis is a genus of flowering plants in the tribe Gnaphalieae within the family Asteraceae. It is endemic to Australia and can be found in every state.

<i>Gompholobium</i> Genus of legumes

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<i>Bossiaea</i> Genus of legumes

Bossiaea is a genus of about 78 species of flowering plants in the pea family Fabaceae and is endemic to Australia. Plants in this genus often have stems and branches modified as cladodes, simple, often much reduced leaves, flowers with the upper two sepal lobes larger than the lower three, usually orange to yellow petals with reddish markings, and the fruit a more or less flattened pod.

<i>Billardiera</i> Genus of plants

Billardiera, commonly known as appleberries, snot berries, or bluebell creepers, is a genus of flowering plants in the family, Pittosporaceae and is endemic to Australia. Plants in the genus Billardiera are woody scramblers, climbers or twiners with elliptic, lance-shaped or linear leaves arranged alternately along the stems, the flowers with petals that are joined to form a tube at the base with spreading lobes, and succulent or fleshy fruit.

<i>Lasiopetalum</i> Genus of flowering plants

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<i>Spyridium</i> Genus of flowering plants

Spyridium is a genus of about thirty species of flowering plants in the family Rhamnaceae, and is endemic to Australia. Plants in the genus Spyridium are shrubs or subshrubs usually with small leaves, flowers usually in clusters of small composite heads, the individual flowers small and densely woolly-hairy, and the fruit a capsule. Species of Spyridium are found in all Australian states except Queensland.

<i>Lepidosperma</i> Genus of grass-like plants

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<i>Styphelia</i> Genus of flowering plants in the heath family Ericaceae

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<i>Vittadinia</i> Genus of flowering plants

Vittadinia is a genus of Australian and New Zealand plants in the tribe Astereae within the family Asteraceae.

References

  1. 1 2 "Olearia Moench". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government.
  2. "Olearia". Integrated Botanical Information System (IBIS). Australian National Botanic Gardens. Retrieved 3 May 2019.
  3. "Olearia". VICFLORA online. Royal Botanic Gardens Victoria. Retrieved 5 May 2019.
  4. Holliday, Ivan. "Olearia". Australian Native Plant Society Australia. Retrieved 9 May 2019.
  5. 1 2 Lander, N.S. "Olearia". PLANTNET. New South Wales Flora Online. Retrieved 9 May 2019.
  6. "Olearia". APNI. Retrieved 18 April 2022.
  7. de Lange, Peter J. "Olearia adenocarpa". New Zealand Plant Conservation Network. Retrieved 19 April 2022.
  8. Cross, E.W.; Quinn, C.J.; Wagstaff, S.J. (2002). "Molecular evidence for the polyphyly of Olearia (Astereae: Asteraceae)". Plant Systematics and Evolution. 235 (1–4): 99–120. doi:10.1007/s00606-002-0198-9. JSTOR   23645039.
  9. "Olearia". Australian Plant Census. Retrieved 1 June 2021.
  10. "Olearia". New Zealand Plant Conservation Network. Retrieved 16 February 2022.
  11. Conn, Barry J. "Census of the Vascular Plants of Papua New Guinea". Royal Botanic Garden Sydney. Retrieved 4 May 2019.
  12. "AGM Plants – Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 69. Retrieved 14 April 2018.
  13. "RHS Plantfinder – Olearia macrodonta" . Retrieved 14 April 2018.
  14. "RHS Plantfinder – Olearia × mollis 'Zennorensis'" . Retrieved 14 April 2018.
  15. "Olearia × scilloniensis". RHS. Retrieved 18 January 2021.
  16. "RHS Plantfinder – Olearia × scilloniensis 'Master Michael'" . Retrieved 14 April 2018.