''Myosotis pulvinaris'' 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 habit, short bracteate inflorescences, and white corollas.

Taxonomy and etymology

''Myosotis pulvinaris''

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

. On the one hand, it is morphologically most similar to the other two cushion- or mat-forming species, ''M. uniflora'' and ''M. glabrescens. Myosotis pulvinaris'' differs from ''M. uniflora'' in its white corollas, and from ''M. glabrescens'' in its short filaments and anthers which are only partially exserted (i.e. the tips only surpassing the faucal scales), and its short calyx lobes which are shorter than half the length of the calyx. ''M. pulvinaris'' is also similar to two other bracteate-prostrate species of ''Myosotis,'' ''M. retrorsa'' and ''M. lyallii.'' ''M. pulvinaris'' - together with ''M. glabrescens'' and ''M. uniflora -'' differ from these two species in their compact cushion or mat habit and short one-flowered inflorescences, as well as leaves that are spirally arranged, imbricate, sheathing, smaller, with the widest point at or below the middle, and with sparsely to densely distributed, untidy, flexuous hairs on the underside. The type specimen of ''Myosotis pulvinaris'' 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 ...

(K000787905). The specific epithet, ''pulvinaris'', is derived from Latin for cushion or pillow and refers to the cushion habit of this species.

Phylogeny

''Myosotis pulvinaris'' 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 four sequenced individuals of ''M. pulvinaris'' did not always form a monophyletic group, but they usually grouped with ''M. glabrescens'' and some of the other bracteate-prostrate species.

Description

''Myosotis pulvinaris'' plants are tightly compacted cushions that can reach 50 cm in diameter. The many imbricate rosette leaves have glabrous petioles 1–7 mm long. The rosette leaf blades are 1–6 mm long by 2–6 mm wide (length: width ratio 0.7–1.5: 1), broadly ovate to very broadly ovate, obovate to very broadly obovate, round, or orbicular, widest at or above the middle, with an obtuse apex. The upper and lower surfaces of the leaf are densely covered in long, flexuous, mostly appressed antrorse (forward-facing) hairs that are oriented parallel to the mid vein; the leaf margin has patent to erect hairs. 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 70 mm long. The cauline leaves are similar to the rosette leaves but smaller, and decrease in size toward the tip. 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 3–5 mm long at flowering and 4–6 mm long at fruiting, lobed to a third to half its length, and densely covered in long, antrorse, flexuous, appressed hairs. The corolla is white, up to 10 mm in diameter, with a cylindrical tube, petals that are narrowly to very broadly obovate or ovate to very broadly ovate, and flat, and small yellow scales alternating with the petals. The anthers are partly exserted, with the tips only surpassing the scales. The four smooth, shiny, dark brown nutlets are 1.3–2.1 mm long by 0.7–1.0 mm wide and narrowly ovoid to ovoid in shape. The chromosome number of ''M. pulvinaris'' is unknown. ''M. pulvinaris'' has ''M. uniflora'' type pollen. It flowers and fruits from October–April, with the main flowering period December–February and the main fruiting period January–March.

Distribution and habitat

''Myosotis pulvinaris'' is a

endemic to the mountains of the South Island of New Zealand. It is mainly found in Otago, but is also known from Westland, Canterbury and Fiordland from 1020–2130 m ASL. ''M. pulvinaris'' is common and locally abundant in subalpine to alpine fellfields and cushionfields in these areas.

Conservation status

The species is listed as "Not Threatened" on the most recent assessment (2017-2018) under the New Zealand Threatened Classification system for plants.

References

External links

''Myosotis pulvinaris'' occurrence data from Australasian Virtual Herbarium
* {{Taxonbar, from=Q17416943 pulvinaris Endemic flora of New Zealand Taxa named by Joseph Dalton Hooker Plants described in 1867