Atriplex hollowayi

Atriplex hollowayi

Nationally Critical (NZ TCS)[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Amaranthaceae
Genus: Atriplex
Species:
A. hollowayi
Binomial name
Atriplex hollowayi
de Lange & D.A.Norton

Atriplex hollowayi, also known as Holloway's crystalwort, is a species of annual herbaceous plant in the genus Atriplex.[2] This species is endemic to New Zealand.[2] It has the "Nationally Critical" conservation status under the New Zealand Threat Classification System.[1]

Description

Atriplex hollowayi is a soft, succulent annual plant. The stem and leaves look like they are coated with sugar crystals.[3] The plant is a many-branch shrub that grows in sand to a diameter of 80–120 cm (31–47 in), the yellow branches themselves 1–5 cm (0.4–2.0 in) long. The smooth, roughly oval leaves are 2–12 mm (0.08–0.47 in) long by 1–6 mm (0.04–0.24 in) wide with irregular dentate (toothed) margins.[4]

Taxonomy

Atriplex hollowayi was described in 2000 by New Zealand botanists Peter de Lange and David Norton, who distinguished it from the widespread Atriplex billardierei. On reviewing the herbarium specimens of the latter species, de Lange noted there were two distinct forms: one with larger leaves with entire margins, and larger bracteoles and seeds, and one with smaller leaves with irregular sinuate-dentate margins and smaller bracteoles and seeds. This latter form was restricted to the North Island, and following field work was described as a new species, its name honouring botanist and conservationist John Stevenson Holloway, who had died in 1999.[4]

Distribution

It inhabits the strand line, the unvegetated stable sand above the high tide line.[3] It was once found on beaches from Northland to Wellington. Now it is only found on one beach, with a population estimated at fewer than 50 plants. The reason for its decline is unknown.[5]

References

  1. ^ a b 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 (1 May 2018). "Conservation status of New Zealand indigenous vascular plants, 2017" (PDF). New Zealand Threat Classification Series. 22: 1–86. OCLC 1041649797.
  2. ^ a b "Atriplex hollowayi de Lange & D.A.Norton". www.nzor.org.nz. Retrieved 24 November 2019.
  3. ^ a b "Holloway's crystalwort (Atriplex hollowayi) conservation factsheet" (PDF). Endangered Species Foundation of New Zealand (ESFNZ). Archived (PDF) from the original on 21 January 2019.
  4. ^ a b de Lange, Peter James; Norton, David A.; Crowcroft, G. M. (2000). "Taxonomy, ecology, and conservation of Atriplex billardierei and A. hollowayi sp. nov. (Chenopodiaceae) in Australasia". New Zealand Journal of Botany. 38 (4): 551–567. Bibcode:2000NZJB...38..551D. doi:10.1080/0028825X.2000.9512704. S2CID 83502268.
  5. ^ "Precarious doomsday solution for native plants". Newsroom. 20 September 2019. Archived from the original on 22 September 2019. Retrieved 24 November 2019.