Prostanthera incisa

{{Short description|Species of flowering plant}} {{Speciesbox |name = Cut-leaved mint-bush |image = Prostanthera incisa 2.jpg |image_caption = Near Bega |genus = Prostanthera |species = incisa |authority = R.Br.<ref name="APC">{{cite web |title=''Prostanthera incisa'' |url=https://biodiversity.org.au/nsl/services/apc-format/display/109975 |website=Australian Plant Census |access-date=3 September 2020}}</ref> |range_map = Prostanthera incisaDistA45.png |range_map_caption = Occurrence data from AVH |synonyms_ref = <ref name="APC" /> | synonyms = {{collapsible list | * ''Prostanthera incisa'' Benth. nom. inval., pro syn. * ''Prostanthera incisa'' R.Br. var. ''incisa'' * ''Prostanthera incisa var. pubescens'' F.Muell. ex Benth. * ''Prostanthera incisa var. sieberi'' (Benth.) C.Moore & Betche * ''Prostanthera sieberi'' Benth. * ''Prostanthera'' sp. aff. ''melissifolia'' * ''Prostanthera violacea'' auct. non R.Br.: Ewart, A.J. (1931) * ''Prostanthera violacea'' var. ''albiflora'' auct. non Benth.: Ewart, A.J. (1931) }} }}

'''''Prostanthera incisa''''', commonly known as '''cut-leaf mint-bush'''<ref name="RBGS">{{cite web |last1=Conn |first1=Barry J. |title=''Prostanthera incisa'' |url=https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Prostanthera~incisa |publisher=Royal Botanic Garden Sydney}}</ref> or '''native thyme''', is a species of flowering plant in the family Lamiaceae and is endemic to south-eastern continental Australia. It is an erect, strongly aromatic, openly branched shrub with hairy, densely glandular branches, egg-shaped to oblong leaves, and pale mauve to mauve flowers.

==Description== ''Prostanthera incisa'' is an erect, openly-branched shrub that typically grows to a height of {{cvt|0.5–3|m}} and {{cvt|2–3|m}} wide. It is a "strongly and rather unpleasantly"<ref name="RBGV">{{cite web |last1=Conn |first1=Barry J. |title=''Prostanthera incisa'' |url=https://vicflora.rbg.vic.gov.au/flora/taxon/6c06fcef-2c39-481c-b76c-1c487c67c4a5 |publisher=Royal Botanic Gardens Victoria |access-date=3 September 2020}}</ref> aromatic shrub or has a "pleasing aroma emanating from the sensitive leaf glands" according to George Althofer.<ref name="GEORGE">{{cite book |last1=Althofer |first1=George |title=Cradle of Incense |date=1978 |publisher=The Society for Growing Australian Plants |isbn=0909830134 |page=71}}</ref> The shrub has ridged, hairy, densely glandular branches. The leaves are hairy, densely glandular, egg-shaped to oblong, paler on the lower surface, {{cvt|8–30|mm}} long and {{cvt|4–12|mm}} wide on a petiole {{cvt|1–10|mm}} long. The edges of the leaves are coarsely toothed and the tip is rounded. The flowers are arranged in bunches near the end of the branches with bracteoles about {{cvt|1|mm}} long but that fall off as the flower develops. The sepals are {{cvt|3–4.5|mm}} long, forming a tube about {{cvt|2|mm}} long with two lobes, the upper lobe about {{cvt|2|mm}} long. The petals are pale mauve to mauve and {{cvt|7–10|mm}} long.<ref name="RBGS" /><ref name="RBGV" />

==Taxonomy== ''Prostanthera incisa'' was first formally described in 1810 by Robert Brown in his book ''Prodromus Florae Novae Hollandiae et Insulae Van Diemen'', and it still bears its original name.<ref name="APNI">{{cite web |title=''Prostanthera incisa'' |url=https://id.biodiversity.org.au/instance/apni/541665 |website=Australian Plant Name Index |access-date=3 September 2020}}</ref><ref name="R.Br.">{{cite book |last1=Brown |first1=Robert |title=Prodromus Florae Novae Hollandiae et Insulae Van Dieman |date=1810 |publisher=typis R. Taylor et socii,1810 |location=London |page=509 |url=https://www.biodiversitylibrary.org/item/21871#page/377/mode/1up |access-date=3 September 2020}}</ref>

==Distribution and habitat== Cut-leaved mint-bush is found along the New South Wales coastline from Mount Warning near the Queensland border all the way to Victoria, as well as on the Central Tablelands of New South Wales.<ref name="RBGS" /> It is found in sheltered sites in rainforest margins or sclerophyll forest under such trees as Sydney blue gum (''Eucalyptus saligna''), cabbage gum (''E. amplifolia''), Sydney peppermint (''E. piperita''), red bloodwood (''Corymbia gummifera'') or turpentine (''Syncarpia glomulifera''). It can also occur in scrub along watercourses in association with river she-oak (''Casuarina cunninghamiana'').<ref name="Cunninghamia">{{cite journal |last1=Benson |first1=Doug |last2=McDougall |first2=Lyn |title=Ecology of Sydney Plant Species, Part 5 - Dicotyledon families Flacourtiaceae to Myrsinaceae |journal=Cunninghamia |date=1997 |volume=5 |issue=2 |page=426 |url=https://www.biodiversitylibrary.org/page/58500872#page/146/mode/1up |access-date=3 September 2020}}</ref>

==Use in horticulture== First grown in England in 1824,<ref name=EJ1997/> ''P. incisa'' var. ''incisa'' is cultivated on a small-scale commercial basis for essential oil production and for bushfood spice. ''P. incisa'' prefers sheltered sites in well-drained acidic soils,<ref name=EJ1997>{{cite book |author1=Elliot, Rodger W. |author2=Jones, David L. |author3=Blake, Trevor |title=Encyclopaedia of Australian Plants Suitable for Cultivation: Volume 7 – N-Po |year=1997 |publisher= Lothian Press |location= Port Melbourne | page=26; 221 |isbn=0-85091-634-8}}</ref> and in poorly drained soils it can be susceptible to root-rot. It has reasonable frost tolerance down to −5 °. It is a fast-growing shrub, and consequently can be harvested within the first year. When pruned back to a height of 50 cm it reshoots readily.

Propagation is by seed or cutting material of firm young growth.<ref name=EJ1997/>

==References== {{Reflist}}

==External links== *{{cite web |title=''Prostanthera incisa'' R.Br. — Cut-Leaved Mint-Bush |publisher=Atlas of Living Australia |url=https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2902306}}

incisa Category:Lamiales of Australia Category:Flora of New South Wales Category:Flora of Victoria (state) Category:Plants described in 1810 Category:Taxa named by Robert Brown (botanist, born 1773)