''Myosotis glauca'' 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,

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

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

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 ...

. George Simpson and J.S. Thomson described ''M. pygmaea'' var. ''glauca'' in 1942, and Peter de Lange and John Barkla recognized it at species rank in 2010. 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 ...

with a prostrate habit, bracteate inflorescences, white corollas, and often

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), g ...

grey leaves.

Taxonomy and etymology

''Myosotis glauca'' (G.Simpson & J.S.Thomson) de Lange & Barkla is in the plant family

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 ...

, was originally described as ''M. pygmaea'' var. ''glauca'' in 1942 by George Simpson and J.S. Thomson, and was later recognized at species rank by Peter de Lange and John Barkla in 2010. In the most recent taxonomic revision, it is continued to be recognized at the species level, and is morphologically most similar to the other bracteate-prostrate species endemic to New Zealand in the pygmy subgroup, i.e. ''Myosotis brevis'' and ''M. antarctica.'' ''Myosotis glauca'' differs from these two species in its straight, appressed trichomes and (usually) glaucous grey leaves. The lectotype specimen of ''Myosotis glauca'' was designated by Lucy Moore and is lodged at the Allan Herbarium (CHR) of Manaaki Whenua - Landcare Research (CHR 75722). There is an isolectotype at the

Auckland War Memorial Museum The Auckland War Memorial Museum Tāmaki Paenga Hira (or simply the Auckland Museum) is one of New Zealand's most important museums and war memorials. Its collections concentrate on New Zealand history (and especially the history of the Aucklan ...

(AK 210591). The specific epithet, ''glauca'', is derived from Latin and refers to the dull greyish-green

leaves of species.

Phylogeny

''Myosotis glauca'' 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. The one sequenced individual of ''M. glauca'' usually grouped with another pygmy subgroup species, ''M. antarctica'' (including ''M. drucei''), as well as with the cushion species, ''M. uniflora,'' among other species. In a study analyzing microsatellite markers developed specifically for the pygmy subgroup of southern hemisphere ''Myosotis'', all populations of ''M. glauca'' cluster together in the different analyses.

Description

''Myosotis glauca'' plants are single rosettes. The rosette leaves have petioles 2–9 mm long. The rosette leaf blades are 4–17 mm long by 2–7 mm wide (length: width ratio 1.3–3.5: 1), narrowly oblanceolate to broadly obovate, widest at or above the middle, dull greyish-green (

) or sometimes bright green, with an obtuse apex. The upper surface of the leaf is sparsely covered in straight, appressed to patent, antrorse (forward-facing) hairs, whereas the lower surface of the leaf is usually glabrous or with sparsely distributed hairs on the mid vein only. Each rosette has multiple prostrate, 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 12 cm long. The cauline leaves are similar to the rosette leaves but decrease in size and become sessile toward the tip. Each inflorescence has up to 19 flowers, each 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 a bract. The calyx is 2–3 mm long at flowering and 3–8 mm long at fruiting, lobed to a quarter or half its length, and usually with hairs only along the calyx ribs. The corolla is white, up to 4 mm in diameter, with a cylindrical tube, and small yellow scales alternating with the petals. The anthers are fully included. The four smooth, shiny, nutlets are usually 1.2–1.5 mm long by 0.8–1.2 mm wide and are ovoid in shape. The chromosome number of ''M. glauca'' is unknown. ''M. glauca'' has ''M. australis'' type pollen. It flowers during the months September–March and fruits October–April, with the main flowering and fruiting period December–January.

Distribution and habitat

''Myosotis glauca'' is a

endemic to the mountains of the South Island of New Zealand. It is mainly found in Otago, but is also known from south Canterbury, from 180–1500 m ASL. ''M. glauca'' is found in tussock-grassland, turf and the edges of tarns or streams.

Conservation status

The species is listed as "Threatened - Nationally Vulnerable" on the most recent assessment (2017-2018) under the New Zealand Threatened Classification system for plants, with the qualifiers "DP" (Data Poor) and "Sp" (Sparse). A recent taxonomic revision recommended maintaining this conservation status, but replacing qualifier "DP" with "RR" (Range Restricted).

References

External links

''Myosotis glauca'' occurrence data from Australasian Virtual Herbarium
* {{Taxonbar, from1=Q17416555, from2=Q96143006 glauca Endemic flora of New Zealand Endangered flora of New Zealand Plants described in 1942