Myosotis eximia

Myosotis eximia is a species of flowering plant in the family Boraginaceae endemic to the North Island of New Zealand. The species was described by Donald Petrie. Plants of this species of forget-me-not are perennial and erect, and have ebracteate inflorescences with white corollas.

Myosotis eximia

Naturally Uncommon (NZ TCS)[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Boraginales
Family: Boraginaceae
Genus: Myosotis
Species:
M. eximia
Binomial name
Myosotis eximia

Taxonomy and Etymology

Myosotis eximia Petrie is in the plant family Boraginaceae and was originally described in 1915 by Donald Petrie.[3][2][4] This species was first collected in December 1914 by Bernard Aston on the slopes of Mt Aorangi, in the Ruahine Ranges, where it formed "continuous patches several feet across, adorned by masses of lovely flowers." at an altitude of 3,900 feet (1,200 m).[2] The species epithet, eximia, means "strikingly unusual".[3]

Phylogeny

Myosotis eximia was shown to be a part of the monophyletic southern hemisphere lineage of Myosotis in phylogenetic analyses of standard DNA sequencing markers (nuclear ribosomal DNA and chloroplast DNA regions).[5] Within the southern hemisphere lineage, species relationships were not well resolved.[5] The chloroplast sequences of the sole individual of M. eximia were more similar to some species with bracteate inflorescences rather than other North Island species with ebracteate inflorescences.[5]

Description

Myosotis eximia is an extensively-branched spreading perennial, which forms clusters of tight rosettes with erect, ebracteate flowering stems.[3] The leaves are sparsely covered in dense, straight hairs that lie flat against the leaf. M. eximia flowers in December and January; its flowers, which Petrie described as "large and showy, white with a yellow eye",[2] have projecting anthers. The anthers are only 2 mm long, much shorter than their filaments.[3]

The chromosome number of M. eximia is 2n = 44.[6]

It flowers from December to January and fruits from February to April.[3]

Distribution and habitat

The species is endemic to New Zealand, and has a very restricted distribution, known only from the Kaimanawa and Ruahine Ranges in the central North Island.[3] It lives in the subalpine to alpine zone, on scree slopes and limestone bluffs.[3] It prefers alkaline soils on limestone or calcareous sandstone.[3]

Conservation status

Myosotis eximia growing in cultivation at Otari-Wilton's Bush.

M. eximia is listed by the Department of Conservation as "At Risk – Naturally Uncommon" on the most recent assessment (2017-2018) of the New Zealand Threat Classification for plants.[1] Its numbers are thought to be stable, with the qualifiers "DP" (Data Poor) and "RR" (Range Restricted).[7] Because of its specialised habitat requirements, its populations are small and localised, but do not seem to be under threat.[3]

Cultivation

This species grows surprisingly well in gardens, preferring soil with some added lime, and is often for sale in native plant nurseries. It needs a sunny, well drained situation, and will flower heavily even in warm climates far from its natural subalpine habitat.[3]

References

  1. Lange, Peter J. de; Rolfe, Jeremy R.; Barkla, John W.; Courtney, Shannel P.; Champion, Paul D.; Perrie, Leon R.; Beadel, Sarah M.; Ford, Kerry A.; Breitwieser, Ilse; Schönberger, Ines; Hindmarsh-Walls, Rowan (May 2018). "Conservation status of New Zealand indigenous vascular plants, 2017" (PDF). New Zealand Threat Classification Series. 22: 1–86. OCLC 1041649797.
  2. Petrie, D. (1916). "Descriptions of New Native Phanerogams". Transactions and Proceedings of the New Zealand Institute. 1915 (sic.) 48: 186–192.
  3. de Lange, Peter (30 April 2022). "Myosotis eximia | New Zealand Plant Conservation Network". NZ Plant Conservation Network. Retrieved 2019-11-24.
  4. Moore, L.B. "Boraginaceae. In 'Flora of New Zealand'. (Ed. HH Allan) Vol. 1, pp. 806–833". (Government Printer: Wellington, New Zealand) floraseries.landcareresearch.co.nz. Retrieved 2022-04-27.
  5. Meudt, Heidi M.; Prebble, Jessica M.; Lehnebach, Carlos A. (2015-05-01). "Native New Zealand forget-me-nots (Myosotis, Boraginaceae) comprise a Pleistocene species radiation with very low genetic divergence". Plant Systematics and Evolution. 301 (5): 1455–1471. doi:10.1007/s00606-014-1166-x. ISSN 2199-6881. S2CID 254048318.
  6. de Lange, P. J.; Murray, B. G. (March 2002). "Contributions to a chromosome atlas of the New Zealand flora—37. Miscellaneous families". New Zealand Journal of Botany. 40 (1): 1–23. doi:10.1080/0028825X.2002.9512767. ISSN 0028-825X.
  7. "Myosotis eximia Petrie". NZTCS. Retrieved 2019-11-29.
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