Myosotis lyallii subsp. lyallii

Myosotis lyallii subsp. lyallii
Conservation status
Naturally Uncommon (NZ TCS) [1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Boraginales
Family:	Boraginaceae
Genus:	Myosotis
Species:	M. lyallii
Subspecies:	M. l. subsp. lyallii
Trinomial name
Myosotis lyallii subsp. lyallii Hook.f. [2]
Synonyms
Myosotis lyallii var. lyallii Myosotis lyallii var. townsonii (Cheeseman) L.B.Moore Myosotis townsonii Cheeseman

Myosotis lyalliisubsp. lyallii is a subspecies of flowering plant in the family Boraginaceae, endemic to the South Island of New Zealand. Joseph Dalton Hooker described M. lyallii in 1853. Plants of this subspecies of forget-me-not are perennial with a prostrate habit, bracteate or partially-bracteate inflorescences, and white corollas, usually with exserted anthers.

Taxonomy and etymology

Myosotis lyallii subsp. lyallii is in the plant family Boraginaceae. The species Myosotis lyallii was described in 1853 by Joseph Dalton Hooker in Flora Novae-Zelandiae . ^{[3] [4] [5]}

The holotype specimen of Myosotis lyallii is lodged at Kew Herbarium (K000357221). ^{[6] [7]}

The specific epithet, lyallii, was chosen to honor David Lyall, who was Joseph Hooker's friend and fellow assistant surgeon on the Ross Expedition, and who collected the type specimen during that voyage. ^[6]

This is one of two subspecies recognized in M. lyallii; the other is M. lyallii subsp. elderi . ^[6] The subspecies are largely allopatric, as M. lyallii subsp. lyallii is generally found in the wet, western side of the main divide of the South Island, whereas M. lyallii subsp. elderi is generally found on the dry, eastern side. ^[6] In M. lyallii subsp. lyallii, the anthers are usually wholly above the faucal scales (fully exserted), whereas in M. lyallii subsp. elderi, the anthers are at least partly below the faucal scales (partially exserted). ^{[6] [3]} Furthermore, M. lyallii subsp. lyallii has longer filaments (> 0.6 mm) and at least some inflorescences that are partially bracteate, compared to filaments < 0.6 mm long and inflorescences that are wholly bracteate in M. lyallii subsp. elderi. ^[6]

Phylogeny

To date, Myosotis lyallii subsp. lyallii has not been included in any published phylogenetic analyses using standard DNA sequencing markers (nuclear ribosomal DNA and chloroplast DNA regions). ^{[8] [9]}

Description

Myosotis lyallii subsp. lyallii plants are rosettes that grow together forming loose clumps. The rosette leaves have petioles usually 3–18 mm long (rarely up to 40 mm long). The rosette leaf blades are 4–27 mm long by 2–13 mm wide (length: width ratio 1.1–3.6: 1), usually narrowly obovate to broadly obovate, usually widest at or above the middle, and usually with an obtuse apex. The upper surface of the leaf are densely covered in long, flexuous (sometimes curved), usually patent, antrorse (forward-facing) hairs that are oriented parallel to the mid vein; the leaf margin and petiole margin have patent to erect hairs. The lower surface of the leaf is similar except it can be glabrous or with isolated hairs on the midrib only. Each rosette has 1–19 prostrate or ascending, unbranched or once-branched, usually partially-bracteate inflorescences that are up to 105 mm long (rarely up to 230 mm long). The cauline leaves (sometimes called bracts) are similar to the rosette leaves but smaller, and decrease in size and become sessile toward the tip. Each inflorescence has 2–15 flowers, each borne on a short pedicel, and each usually with a bract. The calyx is 3–7 mm long at flowering and 4–8 mm long at fruiting, lobed to one-third to two-thirds its length, and densely covered in long, antrorse, mostly flexuous, appressed to patent hairs (sometimes mixed with retrorse or backward-facing hairs, or curved or rarely hooked hairs, on the calyx base). The corolla is white, up to 11 mm in diameter, with a cylindrical tube, petals that are broadly to very broadly ovate or obovate to very broadly obovate, and flat, and small yellow scales alternating with the petals. The anthers are 5–11 mm long and usually fully exserted or sometimes partially exserted, with the tips or upper quarter only surpassing the scales. The filaments are usually 1–2 mm long. The four smooth, shiny, light, medium or dark brown nutlets are 1.1–2.4 mm long by 0.6–1.5 mm wide and narrowly ovoid to ovoid in shape. ^[6]

The chromosome number of M. lyallii subsp. lyallii is unknown.

M. lyallii subsp. lyallii has M. australis type pollen. ^[10]

It flowers and fruits from December–March. ^[6]

Distribution and habitat

Myosotis lyallii subsp. lyallii is a forget-me-not endemic to the mountains of western areas of the South Island New Zealand from 900–1980 m ASL in the following ecological districts: Western Nelson, Westland, Canterbury, and Fiordland. ^[6] M. lyallii subsp. lyallii is an occasional plant in exposed, steep, rocky sites in fellfields and tussock-herbfields. ^[6]

Conservation status

Myosotis lyallii subsp. lyallii is listed as "At Risk - Naturally Uncommon", with the qualifiers "DP" (Data Poor) and "Sp" (Sparse) in the most recent assessment (2017-2018) under the New Zealand Threatened Classification system for plants. ^{[1] [6]}

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: 45. OCLC   1041649797.
2. Hooker, Joseph Dalton (1853). The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror in the Years 1839-1843 :under the command of Captain Sir James Clark Ross. Vol. 2. London: Reeve Brothers. p. 202.
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. "Myosotis lyallii". New Zealand Plant Conservation Network. Retrieved 3 July 2022.
5. Hooker, Joseph Dalton (1853). The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror in the Years 1839-1843 :under the command of Captain Sir James Clark Ross. Vol. 2. London: Reeve Brothers. p. 202.
6. Meudt, Heidi M.; Prebble, Jessica M. (28 February 2018). "Species limits and taxonomic revision of the bracteate-prostrate group of southern hemisphere forget-me-nots (Myosotis, Boraginaceae), including description of three new species endemic to New Zealand". Australian Systematic Botany. 31 (1): 48–105. doi:10.1071/SB17045. ISSN   1446-5701. S2CID   90834744.
7. "Type of Myosotis lyallii Hook.f. on JSTOR". plants.jstor.org. Retrieved 3 July 2022.
8. Winkworth, Richard C; Grau, Jürke; Robertson, Alastair W; Lockhart, Peter J (1 August 2002). "The origins and evolution of the genus Myosotis L. (Boraginaceae)". Molecular Phylogenetics and Evolution. 24 (2): 180–193. doi:10.1016/S1055-7903(02)00210-5. ISSN   1055-7903. PMID   12144755.
9. Meudt, Heidi M.; Prebble, Jessica M.; Lehnebach, Carlos A. (1 May 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   14686750.
10. Meudt, HM (1 October 2016). "Pollen morphology and its taxonomic utility in the Southern Hemisphere bracteate-prostrate forget-me-nots (Myosotis, Boraginaceae)". New Zealand Journal of Botany. 54 (4): 475–497. doi:10.1080/0028825X.2016.1229343. ISSN   0028-825X. S2CID   89118799.

External links

• Myosotis lyallii subsp. lyallii occurrence data from Australasian Virtual Herbarium