Atriplex hollowayi
Common names
Holloway’s crystalwort
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Cream, Green
Detailed description
Annual, succulent, densely branched herb, forming circular 0.8 × 1.2 m mounds on sandy beaches just above mean annual high water tide mark. All exposed parts copiously covered in fine, sugar-like, deciduous, spherical, glistening, ball-like papillae. Branches 10–50 mm long, succulent, creamy yellow, rooting at nodes. Stems pale yellow. Leaves 2–12 × 1–6 mm, grey-green, margins distinctly but irregularly toothed. Plants monoecious. Male flowers axillary, in clusters of 2–4, rarely single; perianth lobes 5, green or pale-cream, 0.8–1 mm, elliptic-oblong; stamens 5, anthers yellow; female flowers minute, 0.8–1.2 mm, shortly stipitate, solitary or paired in leaf-axils. Perianth absent, bracteolea fused for ½ length, lips triangular, obtuse, laciniate, fimbriate to entire; styles 2 not connate; stigmas 2, white, 0.7–1 mm. Fruits 2.8–4.0 × 1.5–2.3, straw-yellow, urceolate, papery. Seed circular, convexm 0.9–2 mm diam., chestnut-brown maturing purple-brown.
Similar taxa
Atriplex billardierei (Moq.) Hook.f., which can be distinguished by its smooth margined leaves, fused, paired stigma, larger fruits and seeds. A. billardierei appears to have never grown in A. hollowayi habitats, and was historically known in New Zealand only from Southland, Stewart Island and Chatham Island sand beaches. Currently it is only known in New Zealand from the Chatham Islands, where it is seasonally abundant.
Distribution
Endemic. North Island, formerly recorded from Te Paki south and east to Hicks Bay, including Mayor (Tuhua) Island, with a disjunct southerly gathering made by Thomas Kirk in the 1800s from Lyall Bay, Wellington. Now known naturally only from Waikuku and Whareana Beaches, on the eastern side of Te Paki.
Habitat
Sandy Beaches, at or just above the high water tide mark. Usually found at or in the vicinity of a fresh water stream draining across a beach
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Threatened – Nationally Critical | Qualifiers: CD, EF, OL
Threats
At risk from trampling and/or browsing by livestock and palatable to most herbivores. There is some historical evidence suggesting that some of this species decline was caused by botanists collecting whole plants—which to an annual species can be a serious threat. Holloway’s crystalwort is also threatened by competition from other introduced strand plants, summer cyclonic storms, human beach users—especially from the ever increasing use of all-terrain vehicles on sand beaches.
Detailed taxonomy
Family
Synonyms
None
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October - February
Fruiting
December–April
Propagation technique
Easily grown from seed that has first been soaked in fresh water. Can be grown from softwood cuttings early in growing season.
Other information
Extra information
Considerable conservation effort has been undertaken by the Department of Conservation following a recovery plan written specifically for this species in 2001. As a result Holloway’s crystalwort has been successfully managed back from the brink of extinction. Plans are underway to reintroduce it to several more southerly locations that fit within its historic range.
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for February 2004 for the full story.
Etymology
atriplex: From an ancient Latin name whose derivation is uncertain, but a possible explanation is the name comes from the Greek a- ‘without’ and traphein ‘nourishment’ because many of these species grow in arid desert soils
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
ATRHOL
Chromosome number
2n = 18
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Critical | Qualifiers: CD, EF, OL
2012 | Threatened – Nationally Critical | Qualifiers: CD, EF, OL
2009 | Threatened – Nationally Vulnerable | Qualifiers: CD, EF, Inc, OL
2004 | Threatened – Nationally Critical
Referencing and citations
References and further reading
de Lange, P.J. ; Norton, D.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: 551–567.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009: Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11(4): 285–309.
Attribution
Description based on de Lange et al. (2000).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Atriplex hollowayi Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/atriplex-hollowayi/ (Date website was queried)