''Myosotis uniflora'' 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 ...

Joseph Dalton Hooker Sir Joseph Dalton Hooker (30 June 1817 – 10 December 1911) was a British botanist and explorer in the 19th century. He was a founder of geographical botany and Charles Darwin's closest friend. For twenty years he served as director of t ...

described the species in 1867. 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, compact, cushion or mat habit, short bracteate inflorescences, and cream to yellow corollas.

Taxonomy and etymology

''Myosotis uniflora''

Hook.f. Sir Joseph Dalton Hooker (30 June 1817 – 10 December 1911) was a British botanist and explorer in the 19th century. He was a founder of geographical botany and Charles Darwin's closest friend. For twenty years he served as director of ...

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 ...

and was described in 1867 by

. It is morphologically most similar to the other two cushion- or mat-forming species, '' M. pulvinaris'' and '' M. glabrescens. Myosotis uniflora'' differs from these two species in its ecology and morphology, including its cream to yellow corollas; acute, lanceolate to ovate narrow (< 1.3 mm) rosette leaf lamina; and narrow petioles (< 1.2 mm wide). The lectotype specimen of ''Myosotis uniflora'' is lodged at

Kew Herbarium Kew Gardens is a botanic garden in southwest London that houses the "largest and most diverse botanical and mycological collections in the world". Founded in 1840, from the exotic garden at Kew Park, its living collections include some of the ...

(K000787907). Two isolectotypes (K000787908 and K000787910) are also found on the same sheet as the lectotype, and a third isolectotype is at the Allan Herbarium of Manaaki Whenua - Landcare Research (CHR 97402). The specific epithet, ''uniflora'', is derived from Latin for 'one-flowered'.

Phylogeny

''Myosotis uniflora'' 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). The two sequenced individuals of ''M. uniflora'' were near but not sister to each other in the nuclear ribosomal DNA phylogeny, grouping with other bracteate-prostrate species such as ''M. glauca'' and ''M. antarctica.'' Within the southern hemisphere lineage, species relationships were not well resolved.

Description

''Myosotis'' plants are compacted cushions or mats that can reach 50 cm in diameter. The many imbricate rosette leaves have petioles 1–4 mm long that are

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 ...

but with erect hairs on the edges. The rosette leaf blades are 1–4 mm long by about 1 mm wide (length: width ratio 1.4–4.1: 1), lanceolate to ovate or triangular, widest at or below the middle, with an

acute Acute may refer to: Science and technology * Acute angle ** Acute triangle ** Acute, a leaf shape in the glossary of leaf morphology * Acute (medicine), a disease that it is of short duration and of recent onset. ** Acute toxicity, the adverse eff ...

apex. The upper and lower surfaces of the leaf are sparsely to densely covered in long, flexuous, appressed to patent, antrorse (forward-facing) hairs that are oriented parallel to the mid vein. Each rosette has few prostrate to ascending, once-branched, 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 60 mm long. The cauline leaves are similar to the rosette leaves but smaller. Each inflorescence has a solitary flower, 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 1–4 mm long at flowering and 2–5 mm long at fruiting, lobed to about half its length, and densely covered in long, antrorse, flexuous (rarely hooked at the calyx base), mostly appressed (few patent) hairs. The corolla is cream to yellow, 2–7 mm in diameter, with a cylindrical tube, petals that are obovate to very broadly obovate or ovate to very broadly ovate, and flat, and small yellow scales alternating with the petals. The anthers are usually fully included, or sometimes partially included with the tips only surpassing the scales. The four smooth, shiny, dark brown nutlets are 1.4–1.7 mm long by 0.8–1.4 mm wide and narrowly ovoid to broadly ovoid in shape. The chromosome number of ''M. uniflora'' is unknown. ''M. uniflora'' has ''M. uniflora'' type pollen. The breeding system of ''Myosotis uniflora'' is

outcrossing Out-crossing or out-breeding is the technique of crossing between different breeds. This is the practice of introducing distantly related genetic material into a breeding line, thereby increasing genetic diversity. Outcrossing can be a useful ...

, as the flowers are 'always herkogamous', with a high pollen : ovule ratio. It flowers and fruits from September–March, with the main flowering period October–January and the main fruiting period November–March.

Distribution and habitat

''Myosotis uniflora'' is a

endemic to the South Island of New Zealand in the ecological districts of Canterbury and Otago from 210–850 m ASL elevation. It is mainly found in Otago, but is also known from Westland, Canterbury and Fiordland from 1020–2130 m ASL. ''M. uniflora'' plants are found scattered throughout lowland river-bed flats and terraces, with other cushions, herbs and subshrubs. They are closely associated with cushionfield, moss-stonefield and stonefield plant communities in upper river catchments.

Conservation status

The species is listed as "At Risk - Naturally Uncommon" on the most recent assessment (2017-2018) under the New Zealand Threatened Classification system for plants, with the qualifiers "Sp" (Sparse) and "DP" (Data Poor).

References

External links

''Myosotis uniflora'' occurrence data from Australasian Virtual Herbarium
* {{Taxonbar, from=Q17416916 uniflora Endemic flora of New Zealand Endangered flora of New Zealand Taxa named by Joseph Dalton Hooker Plants described in 1867