''Myosotis chaffeyorum'' 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

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 ...

. Carlos Lehnebach described the species. Plants of this species of forget-me-not 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 creeping habit, bracteate inflorescences, and white corollas.

Taxonomy and etymology

''Myosotis chaffeyorum'' Lehnebach is in the plant family

and was originally described in 2012 by Carlos Lehnebach. ''M. chaffeyorum'' is morphologically most similar to the other creeping, bracteate-prostrate species, '' M. spatulata, M. matthewsii, M. tenericaulis'' and '' M. albiflora.'' It can be differentiated from the first two by the following characters: anthers fully included or anther tips just reaching faucal scales, filaments < 0.5 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 mm), and seeds that are often darker in color (medium to dark brown v. light to medium brown). The type specimen of ''Myosotis chaffeyorum'' is lodged at the Allan Herbarium (CHR) of Manaaki Whenua - Landcare Research, Lincoln. Anthony Druce collected the type specimen of this species from Takaka Valley in north-west Nelson in 1977. 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.

Phylogeny

''Myosotis chaffeyorum'' 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 Nuclear may refer to: Physics Relating to the Atomic nucleus, nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear ...

and chloroplast DNA regions). Within the southern hemisphere lineage, species relationships were not well resolved. 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 nulcear ribosomal DNA dataset.

Description

''Myosotis chaffeyorum'' plants are single rosettes. The rosette leaves have petioles 5–29 mm long. The rosette leaf blades are 4–17 mm long by 3–16 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 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

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 13–23 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 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 ...

and with a bract. The calyx is 2–3 mm long at flowering and 3–4 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 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 mm long by 0.8–0.9 mm wide and ovoid in shape. ''Myosotis chaffeyorum'' has ''M. uniflora'' type pollen. The chromosome number of ''M. chaffeyorum'' is unknown. It flowers from October to February and fruits in January and February.

Distribution and habitat

''Myosotis chaffeyorum'' is endemic to the South Island of New Zealand in Western Nelson, Sounds-Nelson and Marlborough, from (50–)550–1100 m elevation. ''M. chaffeyorum'' is found on limestone, marble or ultramafic bluffs and rocks, usually on bare, dry soils, in shady places. It is considered to be an obligate

calcicole A calcicole, calciphyte or calciphile is a plant that thrives in lime rich soil. The word is derived from the Latin 'to dwell on chalk'. Under acidic conditions, aluminium becomes more soluble and phosphate less. As a consequence, calcicoles grown ...

Conservation status

The species is listed as Threatened - Nationally Critical the most recent assessment (2017-2018) of the New Zealand Threatened Classification for plants. It also has the qualifiers "DP" (Data Poor), "RR" (Sparse) and "Sp" (Sparse).

References

External links

''Myosotis chaffeyorum'' occurrence data from Australasian Virtual Herbarium
* {{Taxonbar, from=Q17416579 chaffeyorum Endemic flora of New Zealand Endangered flora of New Zealand Plants described in 2012