Olearia

Olearia
Olearia asterotricha in Maranoa Gardens
Scientific classification
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

Synonyms[2]
  • Haxtonia Caley ex G.Don
  • Orestion Raf.
  • Steetzia Sond., nom. illeg.
  • Steiractis Raf.

Olearia, most commonly known as daisy-bush,[3] 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.

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.[4][5][6]

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.[7][8] Originally a large genus, a molecular study has found it to be polyphyletic.[9]

In 2020 Guy L. Nesom named ten new genera – Ephedrides, Eoglandula (later synonymised with the revived Spongotrichum), Landerolaria, Linealia, Muellerolaria, Neolaria, Phaseolaster, Vicinia, Walsholaria, and Wollemiaster – in which to place the 29 paraphyletic species previously in Olearia.[10]

Distribution

As of March 2026 Plants of the World Online accepts 135 species of Olearia in Australia, New Guinea, and New Zealand.[2] PlantNET accepts approximately 180 species, of which about 130 species are endemic to Australia. Olearia are found in all states of Australia.[6]

Species

The following is a list of Olearia species accepted by the Plants of the World Online as of March 2026,[2] 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:[11][12][13]

Formerly placed here

  • Ephedrides trifurcata (Lander) G.L.Nesom (aș Olearia trifurcata Lander)
  • Landerolaria arckaringensis (P.J.Lang) G.L.Nesom – Arckaringensis daisy (S.A.) (as Olearia arckaringensis P.J.Lang)
  • Landerolaria eremaea (Lander) G.L.Nesom (W.A.) (as Olearia eremaea Lander)
  • Landerolaria gordonii (Lander) G.L.Nesom (Qld.) (as Olearia gordonii Lander)
  • Landerolaria humilis (Lander) G.L.Nesom (W.A.) (as Olearia humilis Lander)
  • Landerolaria laciniifolia (Lander) G.L.Nesom (W.A.) (as Olearia laciniifolia Lander)
  • Landerolaria macdonnellensis (D.A.Cooke) G.L.Nesom (N.T.) (as Olearia macdonnellensis D.A.Cooke)
  • Landerolaria newbeyi (Lander) G.L.Nesom (W.A.) (as Olearia newbeyi Lander)
  • Landerolaria orientalis (A.R.Bean & Jobson) G.L.Nesom (Qld.) (as Olearia orientalis A.R.Bean & Jobson)
  • Landerolaria stuartii (F.Muell.) G.L.Nesom (W.A., N.T., S.A., Qld.) (as Olearia stuartii (F.Muell.) Benth.)
  • Landerolaria xerophila (F.Muell.) G.L.Nesom (W.A., Qld.) (as Olearia xerophila (F.Muell.) Benth.)
  • Linealia flocktoniae (Maiden & Betche) G.L.Nesom (as Olearia flocktoniae Maiden & Betche)
  • Macrolearia angustifolia (Hook.f.) Saldivia – teteaweka (N.Z.) (as Olearia angustifolia Hook.f.)
  • Macrolearia chathamica (Kirk) Saldivia (N.Z.) (as Olearia chathamica Kirk)
  • Macrolearia lyallii (Hook.f.) Saldivia – subantarctic tree daisy (N.Z.) (as Olearia lyallii Hook.f.)
  • Macrolearia oporina (G.Forst.) Saldivia (N.Z.) (as Olearia oporina (G.Forst.) Hook.f.)
  • Muellerolaria picridifolia (F.Muell.) G.L.Nesom (W.A., S.A., Vic.) (as Olearia picridifolia (F.Muell.) Benth.)
  • Muellerolaria rudis (Benth.) G.L.Nesom (S.A., N.S.W., Vic.) (as Olearia rudis (Benth.) F.Muell. ex Benth.)
  • Neolaria ferresii (F.Muell.) G.L.Nesom (W.A., N.T., S.A., Qld.) (as Olearia ferresii (F.Muell.) Benth.)
  • Neolaria mucronata (Lander) G.L.Nesom (W.A.) (as Olearia mucronata Lander )
  • Phaseolaster elliptica (DC.) G.L.Nesom – sticky daisy-bush (Qld., N.S.W.) (as Olearia elliptica DC.)
  • Shawia albida (Hook.f.) Sch.Bip. – tanguru (N.Z.) (as Olearia albida (Hook.f.) Hook.f.)
  • Shawia arborescens (G.Forst.) Sch.Bip. – common tree daisy, glossy tree daisy (N.Z.) (as Olearia arborescens (G.Forst.) Cockayne & Laing)
  • Shawia argophylla (Labill.) Baill. – musk daisy-bush, native musk, silver shrub (N.S.W., Vic.) (as Olearia argophylla (Labill.) F.Muell. ex Benth.)
  • Shawia avicenniifolia Raoul – akeake (N.Z.) (as Olearia avicenniifolia (Raoul) Hook.f.)
  • Shawia chrysophylla (DC.) Sch.Bip. (N.S.W., Qld.) (as Olearia chrysophylla (DC.) Benth.)
  • Shawia cydoniifolia (DC.) Sch.Bip. (Qld., N.S.W.) (as Olearia cydoniifolia (DC.) Benth.)
  • Shawia erubescens (Sieber ex Spreng.) Sch.Bip. – pink-tip daisy-bush, moth daisy-bush (S.A., N.S.W., A.C.T., Vic., Tas.) (as Olearia erubescens (Sieber ex Spreng.) Dippel)
  • Shawia furfuracea (A.Rich.) Raoul ex Sch.Bip. – akepiro or Coromandel tree daisy (N.Z.) (as Olearia furfuracea (A.Rich.) Hook.f. or O. townsonii Cheeseman)
  • Shawia ledifolia (DC.) Sch.Bip. – rock daisy bush (Tas.) (as Olearia ledifolia (DC.) Benth.)
  • Shawia myrsinoides (Labill.) Sch.Bip. – blush daisy-bush, silky daisy-bush (N.S.W., A.C.T., Vic., Tas.) (as Olearia myrsinoides (Labill.) F.Muell. ex Benth.)
  • Shawia nummulariifolia (Hook.f.) Sch.Bip. (N.Z.) (as Olearia nummulariifolia (Hook.f.) Hook.f.)
  • Shawia obcordata (Hook.f.) Sch.Bip. (Tas.) (as Olearia obcordata (Hook.f.) Benth.)
  • Shawia paniculata J.R.Forst. & G.Forst. – akiraho (N.Z.) (as Olearia paniculata (J.R.Forst. & G.Forst.) Druce)
  • Shawia persoonioides (DC.) Sch.Bip. (Tas.) (as Olearia persoonioides (DC.) Benth.)
  • Shawia pinifolia (Hook.f.) Sch.Bip. (Tas.) (as Olearia pinifolia (Hook.f.) Benth.)
  • Shawia rosmarinifolia (DC.) Sch.Bip. (Qld., N.S.W.) (as Olearia rosmarinifolia (DC.) Benth.)
  • Shawia solandri (Hook.f.) Sch.Bip. – coastal tree daisy (N.Z.) (as Olearia solandri (Hook.f.) Hook.f.)
  • Shawia virgata (Hook.f.) Sch.Bip. (N.Z.) (as Olearia virgata (Hook.f.) Hook.f.)
  • Shawia viscosa (Labill.) Sch.Bip. – sticky daisy-bush (Vic., Tas.) (as Olearia viscosa (Labill.) Benth.)
  • Spongotrichum glandulosum (Labill.) G.L.Nesom – swamp daisy-bush (S.A., Qld., N.S.W., A.C.T., Vic., Tas.) (as Olearia glandulosa (Labill.) Benth.)
  • Spongotrichum suffruticosum (D.A.Cooke) G.L.Nesom – clustered daisy-bush (S.A., N.S.W., Vic.) (as Olearia suffruticosa D.A.Cooke)
  • Vicinia ciliata (Benth.) G.L.Nesom – fringed daisy-bush (W.A., S.A., Vic., Tas.) (as Olearia ciliata (Benth.) F.Muell. ex Benth.)
  • Walsholaria calcarea (F.Muell. ex Benth.) G.L.Nesom – limestone daisy bush (W.A., S.A., Vic., N.S.W.) (as Olearia calcarea F.Muell. ex Benth.)
  • Walsholaria cuneifolia (A.R.Bean & M.T.Mathieson) G.L.Nesom (Qld.) (as Olearia cuneifolia A.R.Bean & M.T.Mathieson)
  • Walsholaria magniflora (F.Muell.) G.L.Nesom – splendid daisy-bush (W.A., S.A., N.S.W., Vic.) (as Olearia magniflora (F.Muell.) Benth.)
  • Walsholaria muelleri (Sond.) G.L.Nesom – Goldfields daisy, Mueller's daisy bush (W.A., S.A., Vic., N.S.W.) (as Olearia muelleri (Sond.) Benth.)
  • Wollemiaster cordatus (Lander) G.L.Nesom (as Olearia cordata Lander)

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:-[14]

  • Olearia macrodonta, New Zealand holly[15]
  • Olearia × mollis 'Zennorensis', daisy bush 'Zennorensis'[16]
  • Olearia × scilloniensis[17]
  • Olearia × scilloniensis 'Master Michael'[18]

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

References

  1. ^ a b "Olearia Moench". Australian Plant Name Index (APNI), IBIS database. Canberra, Australian Capital Territory: Centre for Plant Biodiversity Research, Australian Government.
  2. ^ a b c "Olearia Moench". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 1 March 2026.
  3. ^ "Olearia". Integrated Botanical Information System (IBIS). Australian National Botanic Gardens. Retrieved 3 May 2019.
  4. ^ "Olearia". VICFLORA online. Royal Botanic Gardens Victoria. Retrieved 5 May 2019.
  5. ^ Holliday, Ivan. "Olearia". Australian Native Plant Society Australia. Retrieved 9 May 2019.
  6. ^ a b Lander, N.S. "Olearia". PLANTNET. New South Wales Flora Online. Retrieved 2 March 2026.
  7. ^ "Olearia". APNI. Retrieved 18 April 2022.
  8. ^ de Lange, Peter J. "Olearia adenocarpa". New Zealand Plant Conservation Network. Retrieved 19 April 2022.
  9. ^ 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.
  10. ^ Nesom, G.L. 2020. New genera from Australian Olearia (Asteraceae: Astereae). Phytoneuron 2020-65: 1–94. Published 19 August 2020. ISSN 2153-733X
  11. ^ "Olearia". Australian Plant Census. Retrieved 1 June 2021.
  12. ^ "Olearia". New Zealand Plant Conservation Network. Retrieved 16 February 2022.
  13. ^ Conn, Barry J. "Census of the Vascular Plants of Papua New Guinea". Royal Botanic Garden Sydney. Retrieved 4 May 2019.
  14. ^ "AGM Plants – Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 69. Retrieved 14 April 2018.
  15. ^ "RHS Plantfinder – Olearia macrodonta". Retrieved 14 April 2018.
  16. ^ "RHS Plantfinder – Olearia × mollis 'Zennorensis'". Retrieved 14 April 2018.
  17. ^ "Olearia × scilloniensis". RHS. Retrieved 18 January 2021.
  18. ^ "RHS Plantfinder – Olearia × scilloniensis 'Master Michael'". Retrieved 14 April 2018.
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