Eucalyptus kochii

Eucalyptus kochii is a mallee that typically grows to a height of {{cvt|8|m}}, rarely a tree to {{cvt|12|m}}, and forms a lignotuber. It has rough, flaky or fibrous, light grey to brown bark on the trunk and larger branches, smooth grey to pink bark on the thinner branches. The adult leaves are arranged alternately, linear to narrow lance-shaped, the same shade of green on both sides, {{cvt|55-115|mm}} long and {{cvt|5-13|mm}} wide tapering to a petiole {{cvt|5-12|mm}} long. The flower buds are arranged in leaf axils, usually in groups of seven, nine or eleven on an unbranched peduncle {{cvt|6-8|mm}} long, the individual buds on pedicels {{cvt|2-3|mm}} long. Mature buds are cylindrical to spindle-shaped, the floral cup {{cvt|4-5|mm}} long and about {{cvt|3-4|mm}} wide with a conical to horn-shaped operculum of similar dimensions. Flowering occurs between October and February and the flowers are white. The fruit is a woody, oval to urn-shaped capsule {{cvt|6-7|mm}} long and {{cvt|5-6|mm}} wide with the valves protruding above rim level.{{cite web |last1=Chippendale |first1=George M. |title=Eucalyptus kochii |url=https://profiles.ala.org.au/opus/foa/profile/Eucalyptus%20kochii |publisher=Flora of Australia. Australian Biological Resources Study, Department of the Environment and Energy, Canberra |access-date=9 August 2019 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331170605/https://profiles.ala.org.au/opus/foa/profile/Eucalyptus%20kochii |url-status=live }}{{cite web |title=Eucalyptus kochii subsp. kochii |url=https://apps.lucidcentral.org/euclid/text/entities/eucalyptus_kochii_subsp._kochii.htm |publisher=Euclid: Centre for Australian National Biodiversity Research |access-date=1 June 2020 |archive-date=20 June 2021 |archive-url=https://web.archive.org/web/20210620212420/https://apps.lucidcentral.org/euclid/text/entities/eucalyptus_kochii_subsp._kochii.htm |url-status=live }}

The species was formally described in 1929 by the botanists Joseph Maiden and William Blakely in Maiden's book, A Critical Revision of the Genus Eucalyptus.{{cite web|title=Eucalyptus kochii|url=https://id.biodiversity.org.au/instance/apni/455289|publisher=APNI|access-date=9 August 2019|archive-date=31 March 2023|archive-url=https://web.archive.org/web/20230331172040/https://biodiversity.org.au/nsl/services/rest/instance/apni/455289|url-status=live}} The specific epithet (kochii) honours Max Koch for his "very keen interest in the flora of South and Western Australia".{{cite book |last1=Maiden |first1=Joseph |title=A Critical Revision of the Genus Eucalyptus (Volume 8) |date=1929 |publisher=New South Wales Government Printer |location=Sydney |page=41 |url=https://www.biodiversitylibrary.org/item/123314#page/71/mode/1up |access-date=9 August 2019 |archive-date=6 March 2019 |archive-url=https://web.archive.org/web/20190306045034/https://www.biodiversitylibrary.org/item/123314#page/71/mode/1up |url-status=live }}

In 1950, Charles Gardner changed the name to E. oleosa var. kochii in the Journal of the Royal Society of Western Australia, but the change has not been accepted by the Australian Plant Census.{{cite web|title=Eucalyptus oleosa var. kochii|url=https://id.biodiversity.org.au/instance/apni/456127|publisher=APNI|access-date=9 August 2019|archive-date=31 March 2023|archive-url=https://web.archive.org/web/20230331170602/https://biodiversity.org.au/nsl/services/rest/instance/apni/456127|url-status=live}}{{cite journal |last1=Gardner |first1=Charles A. |title=The Western Australian Varieties of Eucalyptus oleosa F.Muell. ex Miq. and their essential oils |journal=Journal of the Royal Society of Western Australia |date=1950 |volume=34 |pages=78–79 |url=https://www.biodiversitylibrary.org/item/151108#page/88/mode/1up |access-date=9 August 2019 |archive-date=24 May 2022 |archive-url=https://web.archive.org/web/20220524151756/https://www.biodiversitylibrary.org/item/151108#page/88/mode/1up |url-status=live }} In the same journal, Gardner described E. oleosa var. borealis, the name of which has subsequently been changed to E. kochii subsp. borealis by Dean Nicolle,{{cite web|title=Eucalyptus kochii subsp. borealis|url=https://id.biodiversity.org.au/instance/apni/601207|publisher=APNI|access-date=9 August 2019|archive-date=31 March 2023|archive-url=https://web.archive.org/web/20230331170447/https://biodiversity.org.au/nsl/services/rest/instance/apni/601207|url-status=live}} and E. oleosa var. plenissima, changed to E. kochii subsp. plenissima by Ian Brooker.{{cite web|title=Eucalyptus kochii subsp. plenissima|url=https://id.biodiversity.org.au/instance/apni/455291|publisher=APNI|access-date=9 August 2019|archive-date=31 March 2023|archive-url=https://web.archive.org/web/20230331170454/https://biodiversity.org.au/nsl/services/rest/instance/apni/455291|url-status=live}}

In 2005, Dean Nicolle also described E. kochii subsp. amaryssia and subsp. yellowdinensis, publishing the names in the journal, Australian Systematic Botany.{{cite web|title=Eucalyptus kochii subsp. amaryssia|url=https://id.biodiversity.org.au/instance/apni/601208|publisher=APNI|access-date=9 August 2019|archive-date=31 March 2023|archive-url=https://web.archive.org/web/20230331170512/https://biodiversity.org.au/nsl/services/rest/instance/apni/601208|url-status=live}}{{cite web|title=Eucalyptus kochii subsp. yellowdinensis|url=https://id.biodiversity.org.au/instance/apni/601209|publisher=APNI|access-date=9 August 2019|archive-date=31 March 2023|archive-url=https://web.archive.org/web/20230331170457/https://biodiversity.org.au/nsl/services/rest/instance/apni/601209|url-status=live}}

The five subspecies names recognised by the Australian Plant Census are:

• Eucalyptus kochii subsp. amaryssia D.Nicolle{{cite web|title=Eucalyptus kochii subsp. amaryssia|url=https://biodiversity.org.au/nsl/services/apc-format/display/196861|publisher=Australian Plant Census|access-date=9 August 2019|archive-date=9 August 2019|archive-url=https://web.archive.org/web/20190809204020/https://biodiversity.org.au/nsl/services/apc-format/display/196861|url-status=live}} has fruit with a rounded operculum and very glossy adult leaves with a high oil content;
• Eucalyptus kochii subsp. borealis (C.A.Gardner) D.Nicolle{{cite web|title=Eucalyptus kochii subsp. borealis|url=https://biodiversity.org.au/nsl/services/apc-format/display/177763|publisher=Australian Plant Census|access-date=9 August 2019|archive-date=9 August 2019|archive-url=https://web.archive.org/web/20190809204022/https://biodiversity.org.au/nsl/services/apc-format/display/177763|url-status=live}} has fruit with a conical operculum and very glossy adult leaves;
• Eucalyptus kochii Maiden & Blakely subsp. kochii{{cite web|title=Eucalyptus kochii subsp. kochii|url=https://biodiversity.org.au/nsl/services/apc-format/display/85207|publisher=Australian Plant Census|access-date=9 August 2019|archive-date=9 August 2019|archive-url=https://web.archive.org/web/20190809204018/https://biodiversity.org.au/nsl/services/apc-format/display/85207|url-status=live}} has dull green adult leaves;
• Eucalyptus kochii subsp. plenissima (C.A.Gardner) Brooker{{cite web|title=Eucalyptus kochii subsp. plenissima|url=https://biodiversity.org.au/nsl/services/apc-format/display/85214|publisher=Australian Plant Census|access-date=9 August 2019|archive-date=9 August 2019|archive-url=https://web.archive.org/web/20190809035435/https://biodiversity.org.au/nsl/services/apc-format/display/85214|url-status=live}} has fruit with a rounded operculum and very glossy adult leaves but with a very low oil content;
• Eucalyptus kochii subsp. yellowdinensis D.Nicolle{{cite web|title=Eucalyptus kochii subsp. yellowdinensis|url=https://biodiversity.org.au/nsl/services/apc-format/display/196671|publisher=Australian Plant Census|access-date=9 August 2019|archive-date=9 August 2019|archive-url=https://web.archive.org/web/20190809035437/https://biodiversity.org.au/nsl/services/apc-format/display/196671|url-status=live}} has unusually narrow, glossy green adult leaves but with a low oil content.

Oil mallee is found on flats, depressions, rises and along roadsides from Kondut to near Pindar in the Avon Wheatbelt and Yalgoo biogeographic regions of Western Australia where it grows in sandy-loamy-clay soils over laterite or granite.

This eucalypt is cultivated in plantations for the production of eucalyptus oil. The distilled oil has a very high content of cineole (83-94%).Boland, D.J., Brophy, J.J., and A.P.N. House, Eucalyptus Leaf Oils, 1991, {{ISBN|0-909605-69-6}}{{cite web|url=https://kochiioil.com.au/|title=100% Australian Eucalyptus Oil|access-date=21 October 2017|publisher=Kochii Australian Eucalyptus Oil|archive-date=21 October 2017|archive-url=https://web.archive.org/web/20171021164326/https://kochiioil.com.au/|url-status=live}}

{{Reflist}}

• Byrne, M., "High genetic identities between three oil mallee taxa, Eucalyptus kochii ssp. kochii, ssp. plenissima and E. horistes, based on nuclear RFLP analysis", Heredity, 1999, 82, pp205–211 [http://www.nature.com/hdy/journal/v82/n2/full/6884740a.html]

{{Taxonbar|from=Q5227129}}

kochii

Category:Eucalypts of Western Australia

Category:Myrtales of Australia

Category:Crops originating from Australia

Category:Plants described in 1929

Category:Taxa named by Joseph Maiden