Polyalthia johnsonii

Polyalthia johnsonii is a shrub to about {{cvt|4|m}} tall. The leaves are up to {{cvt|10|cm}} long by {{cvt|3|cm}} wide, dark green and smooth on the upper surface and paler below, and they are held on a petiole, or leaf stem, about {{cvt|3|mm|2}} long. There are six to nine pairs of inconspicuous lateral veins either side of the midrib, and oil dots are visible with a lens. The leaf base is rounded and asymmetric, the tip is acute.{{R|RFK|XUE|FOA|COOPER2}}

Flowers are either solitary or in clusters, produced in the {{botanygloss|axil|leaf axils}}. They are small, about {{cvt|10|mm|2}} diameter, and have six cream petals arranged in two whorls of three. The inner whorl arch forward and join together at their tips, forming a 'roof' over the flower centre. There are about 30–40 stamens about {{cvt|1|mm|2}} long, and six ovaries each with two ovules.{{R|RFK|XUE|FOA|COOPER2}}

The fruit is a berry, or an aggregate of berries, each black, about {{cvt|18|mm}} long and {{cvt|16|mm}} wide, containing up to two seeds about {{cvt|7 by 4|mm|2}}.{{R|RFK|XUE|FOA|COOPER2}}

Flowering occurs from around October through to March or April, and fruit ripen between May and December.{{R|FOA}}

This species was first described in 1891 by the German-born Australian botanist Ferdinand von Mueller, and was published in the journal The Victorian Naturalist.{{R|MUELLER}} In 2012, Bine Xue et al. published a paper discussing the polyphyly of Polyalthia and some other genera in the Annonaceae family, in which this species was renamed and given its current binomial.{{R|XUE}}

The species epithet johnsonii honours the collector of the first specimens of this plant, zoologist Stephen Johnson.{{R|FOA|COOPER2|MUELLER}}

Polyalthia johnsonii is endemic to a very small part of Queensland. It is found in the foothills and the lowlands around the two highest mountains in Queensland, Mount Bartle Frere and Mount Bellenden Ker, where it inhabits well developed rainforest.{{R|FOA|RFK|AVH}}

This species is listed as least concern under the Queensland Government's Nature Conservation Act.{{R|DESQLD}} {{As of|2025|04|14}}, it has not been assessed by the International Union for Conservation of Nature (IUCN).

{{Reflist|28em|refs=

{{cite web |url=https://biodiversity.org.au/nsl/services/rest/name/apni/246293 |title=Polyalthia johnsonii |website=Australian Plant Name Index (APNI) |publisher=Centre for Australian National Biodiversity Research, Australian Government |access-date=14 April 2025}}

{{cite web |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77123049-1 |title=Polyalthia johnsonii (F.Muell.) B.Xue & R.M.K.Saunders |website=Plants of the World Online |publisher=Board of Trustees of the Royal Botanic Gardens, Kew |year=2025 |access-date=14 April 2025}}

{{cite web |url=https://apps.des.qld.gov.au/species-search/details/?id=35590 |title=Species profile—Polyalthia johnsonii |year=2024 |website=Queensland Department of Environment and Science |publisher=Queensland Government |access-date=14 April 2025}}

{{cite web |url=https://apps.lucidcentral.org/rainforest/text/entities/Polyalthia_johnsonii.htm |title=Polyalthia johnsonii |author1=F.A.Zich |author2=B.P.M.Hyland |author3=T.Whiffen |author4=R.A.Kerrigan |author2-link=Bernard Hyland |year=2020 |website=Australian Tropical Rainforest Plants Edition 8 (RFK8) |publisher=Centre for Australian National Biodiversity Research (CANBR), Australian Government |access-date=14 April 2025}}

{{cite web |url=https://profiles.ala.org.au/opus/foa/profile/Polyalthia%20johnsonii |title=Polyalthia johnsonii |last1=Jessup |first1=L.W. |last2=Kodela |first2=P.G. |year=2022 |editor-last1=Kodela |editor-first1=P.G. |website=Flora of Australia |publisher=Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra |access-date=14 April 2025}}

{{cite journal |last1=Xue |first1=Bine |last2=Su |first2=Yvonne C.F. |last3=Thomas |first3=Daniel C. |last4=Saunders |first4=Richard M.K. |title=Pruning the polyphyletic genus Polyalthia (Annonaceae) and resurrecting the genus Monoon |journal=Taxon |date=2012 |volume=61 |issue=5 |pages=1021–1039 |doi=10.1002/tax.615009|bibcode=2012Taxon..61.1021X }}

{{Cite book |last1=Cooper |first1=Wendy |last2=Cooper |first2=William T. |author-link2=William T. Cooper |date=June 2004 |title=Fruits of the Australian Tropical Rainforest |publication-place=Clifton Hill, Victoria, Australia |publisher=Nokomis Editions |isbn=978-0-9581742-1-3 |url=https://www.nokomis.com.au/product/nokomis-published-books/fruits-australian-tropical-rainforest/ |page=22 (as Haplostichanthus johnsonii) }}

{{cite journal |last1=Mueller |first1=Baron von |title=Descriptions of new Australian plants, with occasional other annotations (continued) |journal=The Victorian Naturalist |date=1891 |volume=7 |issue=11 |page=180 |url=https://www.biodiversitylibrary.org/page/30016292}}

{{cite web |title=Search: species: Polyalthia johnsonii {{!}} Occurrence records |url=https://avh.ala.org.au/occurrences/search?taxa=Polyalthia%20johnsonii#tab_mapView |website=Australasian Virtual Herbarium |publisher=Australian Government |access-date=14 April 2025}}

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• [https://avh.ala.org.au/occurrences/search?taxa=Polyalthia+johnsonii#tab_mapView View a map] of herbarium collections of this species at the Australasian Virtual Herbarium
• [https://inaturalist.ala.org.au/observations?taxon_id=1454957 View observations] of this species on iNaturalist
• [https://flickriver.com/search/Polyalthia+johnsonii View images] of this species on Flickriver.com

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johnsonii

Category:Endemic flora of Queensland

Category:Taxa named by Richard M.K. Saunders

Category:Plants described in 2012