''Myosotis pansa'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Boraginaceae Boraginaceae, the borage or forget-me-not family, includes about 2,000 species of shrubs, trees and herbs in 146, to 156 genera with a worldwide distribution. The APG IV system from 2016 classifies the Boraginaceae as single family of the order ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Lucy Moore described the variety ''M. petiolata'' var. ''pansa'' in 1961, and it was raised to species level as ''M. pansa'' by Heidi Meudt, Jessica Prebble, Rebecca Stanley and Michael Thorsen in 2013. Plants of this species of

forget-me-not ''Myosotis'' ( ) is a genus of flowering plants in the family Boraginaceae. The name comes from the Ancient Greek "mouse's ear", which the foliage is thought to resemble. In the northern hemisphere they are colloquially known as forget-me-nots ...

are

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

rosettes with ebracteate (or partially bracteate) inflorescences and white corollas and exserted anthers.

Taxonomy and etymology

''Myosotis pansa'' is in the plant family

and was originally described as a variety of '' Myosotis petiolata'' in 1961 by Lucy Moore. It was raised to species level as ''Myosotis pansa'' (L.B.Moore) Meudt, Prebble, R.J.Stanley and Thorsen in 2013. ''Myosotis pansa'' is morphologically most similar to the other North Island species, ''M. petiolata'' and '' M. pottsiana.'' 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. pansa'': 7.6–14.3 mm; ''M. pottsiana'': 5.3–9.8 mm; and ''M. petiolata'': 4.2–10.5 mm). The lectotype specimen of ''Myosotis pansa'' was collected by

Donald Petrie Donald Mark Petrie (born April 2, 1954) is an American film director and actor. Life and career Petrie was born in New York City, New York, the son of Dorothea (née Grundy), a television producer, actor, and novelist, and Daniel Petrie, a dir ...

, south of Karekare, Waitakere, Auckland, and is lodged at the

Museum of New Zealand Te Papa Tongarewa The Museum of New Zealand Te Papa Tongarewa is New Zealand's national museum and is located in Wellington. ''Te Papa Tongarewa'' translates literally to "container of treasures" or in full "container of treasured things and people that spring fr ...

, Wellington (WELT SP002432).'''' The specific epithet, ''pansa'', is based on the Latin word ''pansus'' which means to spread out. Lucy Moore did not explain why she chose this name, but it could refer to the spreading petal lobes mentioned in her description.'''' Two subspecies are recognized: ''Myosotis pansa'' subsp. ''pansa'' and ''M. pansa'' subsp. ''praeceps''''.'' The subspecies are

allopatric Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

, and can be distinguished from one another based on inflorescence characteristics, i.e. subsp. ''pansa'' has completely ebracteate inflorescences whereas subsp. ''praeceps'' has partially bracteate inflorescences that cauline leaves associated with the lowest 1–3 flowers (and up to 9 flowers).

Phylogeny

''Myosotis pansa'' was shown to be a part of the

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

southern hemisphere lineage of ''Myosotis'' in

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analyses of standard DNA sequencing markers ( nuclear ribosomal DNA and

chloroplast DNA Chloroplast DNA (cpDNA) is the DNA located in chloroplasts, which are photosynthetic organelles located within the cells of some eukaryotic organisms. Chloroplasts, like other types of plastid, contain a genome separate from that in the cell nu ...

regions). Within the southern hemisphere lineage, species relationships were not well resolved. Multiple individuals of both subspecies of ''Myosotis pansa'' were included in two studies that phylogenetically analysed amplified fragment length polymorphisms (AFLPs). In these analyses, ''Myosotis pansa'' was differentiated from ''M. petiolata'' and ''M. pottsiana,'' and the two subspecies were also genetically differentiated.

Description

''Myosotis pansa'' plants are rosettes. The rosette leaves have petioles that are 4–67 mm long. The rosette leaf blades are 5–60 mm long by 4–31 mm wide (length: width ratio 1.1–2.1: 1), usually narrowly obovate, obovate, broadly obovate, widest at or above the middle, with an obtuse and retuse apex. The upper surface of the leaf is uniformly or patchily covered in straight, appressed, antrorse (forward-facing) hairs. The lower surface of the leaf is

glabrous Glabrousness (from the Latin ''glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

. Each rosette has multiple ascending, once-branched or rarely unbranched ebracteate or partially bracteate

inflorescences An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

that are up to 490 mm long. The cauline leaves are similar to the rosette leaves, but become smaller. The flowers are 3–95 per inflorescence and each is borne on a short

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

with or without a bract. The calyx is 2–4 mm long at flowering and 3–9 mm long at fruiting, lobed to half to most of its length, and sparsely to densely covered in straight to curved, appressed to patent, antrorse hairs. The corolla is white and 4–11 mm in diameter, with a cylindrical tube, petals that are usually obovate, broadly obovate or very broadly obovate, and small yellow scales alternating with the petals. The anthers are fully exserted. The four smooth, shiny, usually dark brown nutlets are 1.4–2.1 mm long by 1.0–1.4 mm wide and ovoid to broadly ovoid in shape. The pollen of ''Myosotis pansa'' is unknown. The chromosome number of ''M. pansa'' is 2''n'' = 44 for two Auckland Museum specimens collected from Waitakere, Auckland.

Distribution and habitat

''Myosotis pansa'' is endemic to the North Island of New Zealand from the Waitakere Ranges in Auckland to Waikato and northern Taranaki, from sea level to 200 m ASL. ''M. pansa'' is found on coastal cliffs, coastal scrub nearby grassy slopes''.''

Conservation status

The two subspecies of ''M. pansa'' are listed as Threatened (subsp. ''pansa'' is Nationally Endangered and subsp. ''praeceps'' is Nationally Vulnerable) in the most recent assessment (2017-2018) of the New Zealand Threatened Classification for plants.

References

External links

''Myosotis pansa'' occurrence data from Australasian Virtual Herbarium
{{Taxonbar, from=Q17416949, from2=Q76375609

pansa The Polish Air Navigation Services Agency (PANSA) started its duty in 2007 as an independent unit, after isolating from "Polish Airports". It is running as a state agency which deals with air traffic management (ATM). PANSA's main obligations an ...

Endemic flora of New Zealand Endangered flora of New Zealand Plants described in 1961