{{Short description|Species of flowering plant}} {{Use New Zealand English|date=May 2023}} {{Use dmy dates|date=May 2023}} {{Speciesbox | image = SP089689 Myosotis pottsiana (L.B.Moore) Meudt et al. WELT Te Papa 1174435 233771.jpg | image_caption = Habit and flowers of Myosotis pottsiana | status = NC | status_system = NZTCS | status_ref = <ref>{{Cite journal |last1=Lange |first1=Peter J. de |last2=Rolfe |first2=Jeremy R. |last3=Barkla |first3=John W. |last4=Courtney |first4=Shannel P. |last5=Champion |first5=Paul D. |last6=Perrie |first6=Leon R. |last7=Beadel |first7=Sarah M. |last8=Ford |first8=Kerry A. |last9=Breitwieser |first9=Ilse |last10=Schönberger |first10=Ines |last11=Hindmarsh-Walls |first11=Rowan |date=May 2018 |title=Conservation status of New Zealand indigenous vascular plants, 2017 |url=https://www.doc.govt.nz/globalassets/documents/science-and-technical/nztcs22entire.pdf |journal=New Zealand Threat Classification Series |volume=22 |pages=1–86 |oclc=1041649797}}</ref> | genus = Myosotis | species = pottsiana | authority = ([[L.B.Moore]]) Meudt et al.<ref name=":2" /> | synonyms = ''Myosotis petiolata'' var. ''pottsiana'' L.B.Moore }} '''''Myosotis pottsiana''''' is a species of [[flowering plant]] in the [[Family (taxonomy)|family]] [[Boraginaceae]], [[Endemic species|endemic]] to the [[North Island]] of [[New Zealand]]. [[Lucy Moore (botanist)|Lucy Moore]] described ''Myosotis petiolata'' var. ''pottsiana'' in 1961. Plants of this species of [[Forget-me-nots|forget-me-not]] are [[Perennial plant|perennial]] rosettes with ebracteate inflorescences and white corollas with exserted stamens.
== Taxonomy and etymology == ''Myosotis pottsiana'' (L.B.Moore) Meudt, Prebble, R.J.Stanley & Thorsen is in the plant family [[Boraginaceae]].<ref name=":0">{{Cite web |title=Myosotis pottsiana |url=https://www.nzpcn.org.nz/flora/species/myosotis-pottsiana/ |access-date=2023-05-13 |website=New Zealand Plant Conservation Network |language=en}}</ref> The species was originally described by [[Lucy Moore (botanist)|Lucy Moore]] as a variety of ''M. pansa, Myosotis petiolata'' var. ''pottsiana'' in 1961.<ref name=":2">{{Cite web |last=Moore |first=L.B. |title=Boraginaceae. In 'Flora of New Zealand'. (Ed. HH Allan) Vol. 1, pp. 806–833 |url=https://floraseries.landcareresearch.co.nz/pages/Taxon.aspx?id=_2dd90ab4-331f-4d49-bb31-b0a843e65931&fileName=Flora%201.xml |access-date=2022-04-27 |website=(Government Printer: Wellington, New Zealand) floraseries.landcareresearch.co.nz}}</ref><ref name=":4">{{Cite journal |last1=Meudt |first1=Heidi |last2=Prebble |first2=Jessica |last3=Stanley |first3=Rebecca J. |last4=Thorsen |first4=Mike |date=2013-01-01 |title=Morphological and amplified fragment length polymorphism (AFLP) data show that New Zealand endemic Myosotis petiolata (Boraginaceae) comprises three rare and threatened species |url=https://www.wikidata.org/wiki/Q54687696 |journal=Australian Systematic Botany |volume=26 |issue=3 |pages=210 |doi=10.1071/SB13023|url-access=subscription }}</ref> It was raised to species rank by Heidi Meudt, Jessica Prebble, Rebecca Stanley, and Michael Thorsen in 2013.<ref name=":4" />
The lectotype specimen of ''Myosotis'' ''petiolata'' var. ''pottsiana'' was collected by [[Anthony Peter Druce|Anthony Druce]] in 1956, and the [[holotype]] is lodged at the Allan Herbarium of [[Manaaki Whenua - Landcare Research]] (CHR 87624).''<ref name=":4" />''<ref>{{Cite web |title=Holotype of Myosotis petiolata var. pottsiana |url=https://scd.landcareresearch.co.nz/Specimen/CHR%2087624 |access-date=13 May 2023 |website=Systematics Collections Data, Manaaki Whenua - Landcare Research}}</ref>
''Myosotis pottsiana'' was discovered by Norman Potts and Marc Heginbotham around 1952,<ref name=":3">{{Cite journal |last=Bowen |first=Dawn |date=1985 |title=A Rare Experience: rediscovering Myosotis petiolata var, pottsiana |url=https://bts.nzpcn.org.nz/site/assets/files/22131/well_1985_42__61-63.pdf |journal=Wellington Botanical Society Bulletin |volume=42 |pages=61–63}}</ref> and the variety and now species epithet honours Potts, who also collected and cultivated it.<ref name=":4" />
''Myosotis pottsiana'' is morphologically and genetically most similar to ''[[Myosotis pansa|M. pansa]]'' and ''[[Myosotis petiolata|M. petiolata]].<ref name=":4" />'' These three species are allopatric in their geographic distributions, and can be distinguished from one another by a suite of characters that includes corolla diameter (''M. pottsiana'': 5.3–9.8 mm; ''M. petiolata'': 4.2–10.5 mm; and ''M. pansa'': 7.6–14.3 mm).<ref name=":4" />
== Phylogeny == Two individuals of ''Myosotis pottsiana'' have been included in [[Phylogenetics|phylogenetic]] analyses of standard DNA sequencing markers ([[Ribosomal DNA|nuclear ribosomal DNA]] and [[chloroplast DNA]] regions).<ref name=":1">{{Cite journal |last1=Meudt |first1=Heidi M. |last2=Prebble |first2=Jessica M. |last3=Lehnebach |first3=Carlos A. |date=2015-05-01 |title=Native New Zealand forget-me-nots (Myosotis, Boraginaceae) comprise a Pleistocene species radiation with very low genetic divergence |url=https://doi.org/10.1007/s00606-014-1166-x |journal=Plant Systematics and Evolution |language=en |volume=301 |issue=5 |pages=1455–1471 |doi=10.1007/s00606-014-1166-x |issn=2199-6881|url-access=subscription }}</ref>
In addition, several individuals of ''Myosotis pottsiana'' were included in two different studies that phylogenetically analysed [[amplified fragment length polymorphism]]s (AFLPs) of the informal ''M. petiolata'' species group.<ref name=":4" /><ref name=":1" /> In these analyses, ''Myosotis pottsiana'' was genetically differentiated from ''[[Myosotis pansa|M. pansa]]'' and ''[[Myosotis petiolata|M. petiolata]]''.'''<ref name=":4" /><ref name=":1" />'''
== Description == '''''Myosotis pottsiana''''' plants are rosettes. The rosette leaves have [[Petiole (botany)|petioles]] that are 14–57 mm long. The rosette leaf blades are 7–51 mm long by 5–32 mm wide (length: width ratio 1.2–2.0: 1), usually narrowly obovate, obovate, broadly obovate, widest at or above the middle, with an [[Glossary of leaf morphology#obtuse|obtuse]] and [[mucronate]] apex. Both surfaces of the leaf are uniformly and densely covered in straight, appressed, antrorse (forward-facing) hairs'''.''' Each rosette has multiple ascending''',''' branched ebracteate (or sometimes partially bracteate) [[inflorescence]]s that are up to 430 mm long. The cauline leaves are similar to the rosette leaves, but become smaller. The flowers are 6–73 per inflorescence, and each is borne on a short [[Pedicel (botany)|pedicel]] without a bract (or sometimes lowest flowers with a bract). The calyx is 2–4 mm long at flowering and 3–5 mm long at fruiting, lobed to half to three-quarters of its length, and densely covered in straight to curved, appressed to patent, antrorse hairs. The corolla is white and 7–15 mm in diameter, with a cylindrical tube, petals that are narrowly ovate, ovate, obovate or broadly obovate, and small yellow scales alternating with the petals. The anthers are fully exserted. The four smooth, shiny, usually medium to dark brown nutlets are 1.3–1.8 mm long by 0.9–1.2 mm wide and ovoid to broadly ovoid in shape.<ref name=":4" />
The pollen of ''Myosotis pottsiana'' is unknown.
The chromosome number of ''M. pottsiana'' is 2''n'' = 44.<ref>{{Cite Q|Q114954860}}</ref>
== Distribution and habitat == Although once thought to be extinct,<ref name=":3" /> ''Myosotis pottsiana'' is known from a handful of populations in Bay of Plenty, North Island, New Zealand from 40 to 300 m ASL, on vertical rock walls, steep river banks and forest bluffs''.''<ref name=":4" /><ref name=":3" />
== Conservation status == ''Myosotis pottsiana'' is listed as Threatened - Nationally Critical in the most recent assessment (2017-2018) of the [[New Zealand Threat Classification System|New Zealand Threatened Classification]] for plants.<ref name=":0" /> The qualifiers "EF" (Extreme fluctuations) and "Sp" (Sparse) are also attached to the assessment.<ref name=":0" />
== Gallery == <gallery mode="packed-hover" heights="170"> File:Myosotis pottsiana - Benjamin Lavin - 469009691.jpeg|Flowers File:Myosotis pottsiana - Benjamin Lavin - 469009696.jpeg|Flowers, side view File:SP089688 Myosotis pottsiana (L.B.Moore) Meudt et al. WELT Te Papa 1174433 233663.jpg|Inflorescence File:Myosotis pottsiana - Benjamin Lavin - 469008297.jpeg|Leaves File:Myosotis pottsiana - Benjamin Lavin - 469008289.jpeg|Upper leaf surface, showing straight, appressed hairs File:Myosotis pottsiana - Benjamin Lavin - 469008292.jpeg|Lower leaf surface File:SP089689 Myosotis pottsiana (L.B.Moore) Meudt et al. WELT Te Papa 1174435 233769.jpg|Habit and habitat </gallery>
== References == {{Reflist}}
== External links == {{Commons}} * [https://avh.ala.org.au/occurrences/search?taxa=myosotis+pottsiana#tab_mapView ''Myosotis pottsiana'' occurrence data from Australasian Virtual Herbarium]
{{Taxonbar|from=Q17416945}}
[[Category:Myosotis|pottsiana]] [[Category:Endemic flora of New Zealand]] [[Category:Endangered flora of New Zealand]] [[Category:Plants described in 1961]]