Myosotis traversii subsp. traversii
Flowering plant of Myosotis traversii subsp. traversii

Not Threatened (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. traversii
Subspecies:
M. t. subsp. traversii
Trinomial name
Myosotis traversii subsp. traversii
Synonyms

Myosotis traversii var. traversii

Myosotis traversii subsp. traversii is a subspecies of flowering plant in the family Boraginaceae, endemic to the northern South Island of New Zealand. Joseph Dalton Hooker described the species M. traversii in 1864. Plants of this subspecies of forget-me-not are perennial rosettes which form tufts or clumps, with ebracteate, erect inflorescences, and white or yellow corollas with partly exserted stamens.

Taxonomy and etymology

Myosotis traversii Hook.f. subsp. traversii is in the plant family Boraginaceae.[3] The species M. traversii was described by Joseph Dalton Hooker in 1864 in his Handbook of the New Zealand Flora.[4]

The lectotype of M. traversii was designated by Lucy Moore, was collected by Leonard Cockayne in the Shingly Range, South Island, and is lodged at the herbarium of the Museum of New Zealand Te Papa Tongarewa (WELT SP002603).[4][5] There is also an isolectotype at the Allan Herbarium of Manaaki Whenua - Landcare Research (CHR 328277).[4][6]

The specific epithet, traversii, honors William Thomas Locke Travers (1819–1903), who was a lawyer, explorer and naturalist who immigrated to New Zealand and collected plants there.[4][7]

This is one of two subspecies recognized in Myosotis traversii; the other is M. traversii subsp. cantabrica.[4] The subspecies are allopatric, with M. traversii subsp. cantabrica found in central South Island in Canterbury, Westland and Otago (from about 43°S to 45°S), and M. traversii subsp. traversii found in northern South Island in Western Nelson, Marlborough, Canterbury and Westland (from about 41°S to 42.5°S).[8]

Myosotis traversii subsp. traversii can be distinguished from M. traversii subsp. cantabrica by its lack of hooked hairs on the underside of the uppermost cauline leaves, and lack of retrorse (backward-facing) hairs on the underside of the lowermost cauline leaves. By contrast, M. traversii subsp. cantabrica plants have hooked hairs on the underside of the uppermost cauline leaves, and the also have retrorse (backward-facing) hairs on the underside of the lowermost cauline leaves.[4]

Phylogeny

The sole individual of Myosotis traversii sampled for phylogenetic analysis was an individual of M. traversii subsp. cantabrica, and 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).[9] Within the southern hemisphere lineage, species relationships were not well resolved.[9] M. traversii subsp. traversii has not yet been included in a phylogenetic analysis.

Description

Myosotis traversii subsp. traversii plants are single rosettes often cluster together to form clumps or tufts. The rosette leaves have petioles 4–29 mm long. The rosette leaf blades are 5–33 mm long by 3–12 mm wide (length: width ratio 1.5–4.5: 1), usually oblanceolate, narrowly obovate, or obovate, widest at or above the middle, with an obtuse apex. The upper surface and the edges of the leaf are densely covered in mostly flexuous and patent, antrorse (forward-facing) hairs that are oriented mostly oblique to the mid vein. The lower surface of the leaf has similar hairs except they are completely retrorse (backward-facing) or they are mostly retrorse with some antrorse hairs near the apex only. Each rosette has 1–7 erect, usually once-branched ebracteate inflorescences that are up to 160 mm long and are usually bifurcating in an open or condensed forked 'V' shape near the tips. The scape has mostly flexuous (few curved), antrorse, appressed to patent, densely distributed hairs. The cauline leaves are up to 13 per inflorescence and are similar to the rosette leaves but smaller with shorter petioles, and decrease in size and become sessile toward the tip. The underside of the cauline leaves have hairs that are not hooked and are mostly antrorse. Each inflorescence has up to 50 flowers, each borne on a pedicel up to 2 mm long at fruiting, and each without a bract. The hairs on the pedicel are flexuous, antrorse, patent and densely distributed. The calyx is 3–7 mm long at flowering and 4–9 mm long at fruiting, lobed to one-third to one-half its length, and densely covered in antrorse hairs (with some retrorse near the base) that are appressed to patent and flexuous, or patent to erect and hooked. The corolla is white or yellow, up to 8 mm in diameter, with a cylindrical tube, petals that are broadly ovate, very broadly ovate., broadly obovate, broadly obovate or very broadly obovate, and small yellow or light yellow scales alternating with the petals. The stamens are 7–10 mm long (measured from the base of the calyx to the anther tips) with filaments 0.3–0.8 mm long. The anthers are partly exserted with the tips only surpassing or equaling the scales. The four smooth, shiny, medium to dark brown nutlets are 2.1–2.7 mm long by 1.2–1.8 mm wide and narrowly ovoid or ovoid in shape.[4]

The chromosome number of M. traversii subsp. traversii is 2n = 44 (CHR 100421).[10][11]

The pollen of M. traversii subsp. traversii is unknown.

It flowers and fruits from November–March, with the main flowering and fruiting period from December–January.[4]

Distribution and habitat

Myosotis traversii subsp. traversii is a forget-me-not endemic to the South Island, in Marlborough, Western Nelson, Canterbury and Westland usually from 1100–2040 m ASL, on scree, shingle, rocks, or saddles.[4]

Conservation status

Myosotis traversii subsp. traversii is listed as Not Threatened (as M. traversii) on the most recent assessment (2017-2018) under the New Zealand Threatened Classification system for plants, with the qualifier "DP" (Data Poor). in the most recent assessment (2017-2018) under the New Zealand Threatened Classification system for plants.[1][4]

References

  1. 1 2 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: 45. OCLC 1041649797.
  2. ↑ Hooker, Joseph Dalton (1864), Handbook of the New Zealand Flora, Lovell Augustus Reeve, Wikidata Q5891734
  3. ↑ 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 27 April 2022.
  4. 1 2 3 4 5 6 7 8 9 10 Meudt, Heidi (2021). "Taxonomic revision of five species groups of ebracteate-erect Myosotis (Boraginaceae) endemic to New Zealand, based on morphology, and description of new subspecies". Australian Systematic Botany. 34 (3): 252–304. doi:10.1071/SB20028. S2CID 234771910.
  5. ↑ "Lectotype of Myosotis traversii". collections.tepapa.govt.nz. Retrieved 26 September 2022.
  6. ↑ "Isolectotype of Myosotis traversii". scd.landcareresearch.co.nz. Retrieved 26 September 2022.
  7. ↑ "Travers, William Thomas Locke". teara.govt.nz. Retrieved 26 September 2022 – via New Zealand Ministry for Culture and Heritage Te Manatu Taonga.
  8. ↑ Meudt, Heidi (2021). "Taxonomic revision of five species groups of ebracteate-erect Myosotis (Boraginaceae) endemic to New Zealand, based on morphology, and description of new subspecies". Australian Systematic Botany. 34 (3): 252–304. doi:10.1071/SB20028. S2CID 234771910.
  9. 1 2 Meudt, Heidi M.; Prebble, Jessica M.; Lehnebach, Carlos A. (2015). "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.
  10. ↑ "Myosotis traversii". scd.landcareresearch.co.nz. Retrieved 27 September 2022.
  11. ↑ E. J. Beuzenberg; J. Hair (1983). "Contributions to a chromosome atlas of the New Zealand flora - 25 miscellaneous species". New Zealand Journal of Botany. 21: 13–20. ISSN 0028-825X. Wikidata Q111822513.
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