{{Short description|Species of flowering plant}} {{Use New Zealand English|date=July 2024}} {{Use dmy dates|date=April 2022}} {{Speciesbox | image = Myosotis chaffeyorum and close-up view of vegetative and reproductive structures.jpeg | image_caption = Vegetative and reproductive features of ''M. chaffeyorum'' | status = NC | status_system = NZTCS | status_ref = <ref name="NZTCS"/> | genus = Myosotis | species = chaffeyorum | authority = [[Carlos Adolfo Lehnebach|Lehnebach]]<ref name=":0"/> }}

'''''Myosotis chaffeyorum''''' is a species of [[flowering plant]] in the [[Family (taxonomy)|family]] [[Boraginaceae]], [[Endemic species|endemic]] to the [[South Island]] of [[New Zealand]]. [[Carlos Adolfo Lehnebach|Carlos Lehnebach]] described the species in 2012. Plants of this species of [[Forget-me-nots|forget-me-not]] are [[Perennial plant|perennial]] with a creeping habit, bracteate inflorescences, and white corollas.

== Description == ''M. chaffeyorum'' plants are single rosettes. The rosette leaves have [[Petiole (botany)|petioles]] 5–29&nbsp;mm long. The rosette leaf blades are 4–17&nbsp;mm long by 3–16&nbsp;mm wide (length: width ratio 1.1–1:5 1), broadly elliptic, orbicular, obovate or very broadly obovate, widest at or above the middle, with an [[Glossary of leaf morphology#obtuse|obtuse]] apex. The upper surface of the leaf is densely covered in straight, appressed, antrorse (forward-facing) hairs that are angled away from the mid vein, while on the lower surface the hairs are the same but oriented parallel to the mid vein. Each rosette has 3–7 sprawling, creeping, ascending or prostrate, unbranched or branched, bracteate [[inflorescence]]s that are 13–23&nbsp;cm long. The cauline leaves on the lower part of the inflorescence are similar to but smaller than the rosette leaves, and decrease in size toward the tip. There can be up to 17 flowers in each inflorescence, each one borne on a short [[Pedicel (botany)|pedicel]] and with a bract.

The calyx is 2–3&nbsp;mm long at flowering and 3–4&nbsp;mm long at fruiting, lobed to slightly more than half of its length, and densely covered in short, straight, antrorse hairs. The corolla is white up to 5&nbsp;mm in diameter, with a cylindrical tube, petals that are rounded and flat, and small yellow scales alternating with the petals. The anthers are partly exserted, with the tips or the upper half only surpassing the scales. The four smooth, shiny, brown or dark brown nutlets are 1.2–1.5&nbsp;mm long by 0.8–0.9&nbsp;mm wide and ovoid in shape.<ref name=":2" /> ''M. chaffeyorum'' has ''M. uniflora'' type pollen.<ref>{{Cite journal |last=Meudt |first=HM |date=2016-10-01 |title=Pollen morphology and its taxonomic utility in the Southern Hemisphere bracteate-prostrate forget-me-nots (Myosotis, Boraginaceae) |url=https://doi.org/10.1080/0028825X.2016.1229343 |journal=New Zealand Journal of Botany |volume=54 |issue=4 |pages=475–497 |doi=10.1080/0028825X.2016.1229343 |issn=0028-825X |s2cid=89118799|url-access=subscription }}</ref><ref>{{Cite web |title=Myosotis chaffeyorum pollen |url=https://collections.tepapa.govt.nz/topic/10503 |access-date=2022-05-01 |website=collections.tepapa.govt.nz}}</ref> It flowers from October to February and fruits in January and February.<ref name=":2" />

<gallery mode="packed" heights="170"> File:SP105614 Myosotis chaffeyorum Lehnebach WELT Te Papa 1592404 400187.jpg|Floral detail File:SP105614 Myosotis chaffeyorum Lehnebach WELT Te Papa 1592404 400186.jpg|Habit File:SP105614 Myosotis chaffeyorum Lehnebach WELT Te Papa 1592404 400204.jpg|Rosette leaves File:SP095613 Myosotis chaffeyorum Lehnebach WELT Te Papa 1315160 389808.jpg|Pollen grain </gallery>

== Taxonomy == ''M. chaffeyorum'' is in the plant family [[Boraginaceae]] and was originally described in 2012 by [[Carlos Adolfo Lehnebach|Carlos Lehnebach]].<ref>{{Cite web |title=Myosotis chaffeyorum |url=https://www.nzpcn.org.nz/flora/species/myosotis-chaffeyorum/ |access-date=2022-05-03 |website=New Zealand Plant Conservation Network |language=en}}</ref><ref name=":0" /> ''M. chaffeyorum'' is morphologically most similar to the other creeping, bracteate-prostrate species, ''[[Myosotis spatulata|M. spatulata]], [[Myosotis matthewsii|M. matthewsii]], M. tenericaulis'' and ''[[Myosotis albiflora|M. albiflora]].'' It can be differentiated from the first two by the following characteristics: anthers fully included or anther tips just reaching faucal scales, filaments < 0.5&nbsp;mm, and lack of hooked trichomes on the base of calyx. ''M. chaffeyorum'' can be distinguished from ''M. tenericaulis'' and ''M. albiflora'' by the length : width ratio of the rosette leaf lamina (1.0–1.4 : 1 vs. 1.5–3.6 : 1), partially included anthers with tips only surpassing the faucal scales (vs. fully included anthers wholly below the scales), longer filaments (0.3–0.5 v. 0.0–0.3&nbsp;mm), and seeds that are often darker in colour (medium to dark brown v. light to medium brown).<ref name=":2" />

The type specimen of ''M. chaffeyorum'' is lodged at the Allan Herbarium (CHR) of [[Manaaki Whenua – Landcare Research|Manaaki Whenua - Landcare Research]], Lincoln.<ref>{{Cite web |title=Myosotis chaffeyorum |url=https://scd.landcareresearch.co.nz/Specimen/CHR%20311719?collection=CHR&searchCollection=CHR&query=311719&currentDisplayTab=list&pageNumber=0&sortField=relevance |access-date=2022-05-01 |website=scd.landcareresearch.co.nz}}</ref><ref name=":2">{{Cite journal |last1=Meudt |first1=Heidi M. |last2=Prebble |first2=Jessica M. |date=2018-02-28 |title=Species limits and taxonomic revision of the bracteate-prostrate group of southern hemisphere forget-me-nots (Myosotis, Boraginaceae), including description of three new species endemic to New Zealand |url=https://www.publish.csiro.au/sb/SB17045 |journal=Australian Systematic Botany |language=en |volume=31 |issue=1 |pages=48–105 |doi=10.1071/SB17045 |s2cid=90834744 |issn=1446-5701|url-access=subscription }}</ref> [[Anthony Peter Druce|Anthony Druce]] collected the type specimen of this species from Takaka Valley in north-west Nelson in 1977.<ref name=":2" />

The [[specific epithet]], ''chaffeyorum'', is named after two people: Annie Selina Chaffey (1877–1953) and Henry Fox Chaffey (1868–1951) who lived in the area where this species is found.<ref name=":0">{{Cite journal |last=Lehnebach |first=Carlos A. |date=2012-08-21 |title=Two new species of forget-me-nots (Myosotis, Boraginaceae) from New Zealand |journal=PhytoKeys |issue=16 |pages=53–64 |doi=10.3897/phytokeys.16.3602 |issn=1314-2011 |pmc=3492931 |pmid=23233811 |doi-access=free }}</ref><ref>{{Cite web |last= |first= |title=Chaffey, Annie Selina and Chaffey, Henry Fox |url=https://teara.govt.nz/en/biographies/4c15/chaffey-annie-selina |access-date=2022-05-01 |website=teara.govt.nz |language=en}}</ref>

=== Phylogeny === ''M. chaffeyorum'' was shown to be a part of the [[monophyletic]] southern hemisphere lineage of ''Myosotis'' 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 |s2cid=14686750 |issn=2199-6881|url-access=subscription }}</ref> Within the southern hemisphere lineage, species relationships were not well resolved.<ref name=":1" /> The sequences of ''M. chaffeyorum'' grouped with individuals of other northern South Island species in both datasets, as well as some North Island species in the nuclear ribosomal DNA dataset.<ref name=":1" />

== Distribution and habitat == ''M. chaffeyorum'' is endemic to the South Island of New Zealand in Western Nelson, Sounds-Nelson and Marlborough, from (50–)550–1100 m elevation.<ref name=":2" /> ''M. chaffeyorum'' is found on limestone, marble or ultramafic bluffs and rocks, usually on bare, dry soils, in shady places.<ref name=":2" /> It is considered to be an obligate [[calcicole]].<ref>{{Cite journal |last1=Rogers |first1=GM |last2=Courtney |first2=SP |last3=Heenan |first3=PB |date=2018 |title=The calcicolous vascular flora of New Zealand |url=https://www.doc.govt.nz/globalassets/documents/science-and-technical/sfc331entire.pdf |journal=Science for Conservation |publisher=Department of Conservation, Te Papa Atawhai, New Zealand Government |publication-place=Wellington, New Zealand |volume=331}}</ref>

== Conservation status == The species is listed as Threatened - Nationally Critical the most recent assessment (2017-2018) of the [[New Zealand Threat Classification System|New Zealand Threatened Classification]] for plants. It also has the qualifiers "DP" (Data Poor), "RR" (Sparse) and "Sp" (Sparse).<ref name="NZTCS">{{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>

== References == {{Reflist}}

== External links == * [https://avh.ala.org.au/occurrences/search?taxa=myosotis+chaffeyorum#tab_mapView ''Myosotis chaffeyorum'' occurrence data from Australasian Virtual Herbarium] * {{Commons category-inline}}

{{Taxonbar|from=Q17416579}}

[[Category:Myosotis|chaffeyorum]] [[Category:Endemic flora of New Zealand]] [[Category:Endangered flora of New Zealand]] [[Category:Plants described in 2012]]