Atriplex billardierei
Common names
crystalwort
Biostatus
Native
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Cream, Green
Detailed description
Decumbent, sprawling, lightly branched, succulent, leafy, monoecious, annual herb, forming circular mats or low mounds within sand, to 2 or 3 m diameter. Branches 20–150 mm long, succulent, cream or yellow, rooting at nodes; exposed surfaces coated with deciduous, watery, spherical, glistening papillae. Leaves 5–20 × 2–7 mm, oblong-obovate, ovate, elliptic, or lanceolate, green to glaucous-green, succulent. Petioles short, 0.5–1 mm. Leaf surface sparsely to densely covered in deciduous watery, spherical, glistening papillae; apex and base obtuse; margin entire, very rarely within one or two lobes. Male flowers axillary, in clusters of 3–4, rarely single; occasionally with rudimentary stigma; perianth lobes 5, green or pale cream, 1.2 mm long, elliptic-oblong, apex inflexed, cucullate, margins laciniate-crenate, abaxial surface covered in watery papillae; stamens 5, filaments 0.6 mm long, white, anthers 0.2 mm long, oblong, basifixed, pollen sulphur yellow. Female flowers minute, 1–2 mm, shortly stipitate, borne in leaf axils, either solitary, or in pairs, usually accompanied by a short shoot with one pair of reduced leaves. Peduncles minute, 0.25 mm long. Perianth absent; bracteoles fused for ¾ of their length, lips entire; external bracteole surfaces glistening, papillae 0.2–0.3 mm diameter; style connate, stigmas 2.1-1.3 mm, white, half exserted, tapering-terete, 0.1–0.2 mm diameter, exserted portion with antrorse papillae. Ovary flattened at right angles to lips, 0.5 mm diameter, sessile or almost so. Fruiting bracteoles 3.3–9.5 × 2.2–6.0 mm, light brown or tan, subsessile or shortly stipitate; urceolate, valves rigidly fused for ¾ of their length, swollen toward base, corky, otherwise coriaceous with an entire margin, apex usually entire, rarely finely crenate, or fimbriate; surface densely coated in watery papillae 0.2–0.3 mm diameter. Seed circular in outline, convex, 1.8–4.0 mm diameter, testa chesnut-brown, maturing purple-brown, fading to black in dried specimens, surface matt, ± smooth. or finely rugose; radicle lateral, erect.
Similar taxa
Atriplex prostrata DC. often grows in similar habitats but has large arrowhead shaped leaves. Atriplex buchananii (Kirk) Cheeseman has been confused with A. billardierei but it lacks the distinctive spherical pustules on the leaves; also it has smaller fruit. Cakile edentula (Bigelow) Hook. and Cakile maritima Scop. are introduced plants that occupy similar habitats.
Distribution
Indigenous. New Zealand: South Island (formerly present in the Foveaux Strait area), Stewart Island/Rakiura (last seen in that area in 1982), Chatham Islands. Also in Australia (Tasmania, apparently extinct elsewhere).
Habitat
It is generally found in the strand zone on open beaches and sandy banks through the build up of sand where it forms low sandy mounds.
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 Endangered | Qualifiers: DPS, DPT, EF, TO
Threats
Possibly very vulnerable to human disturbance. Wide-scale coastal erosion and storm inundation are probably the greatest natural threats. It is occasionally browsed by sheep and cattle and horses. There is evidence from Australia and New Zealand that it is susceptible to competition from other introduced strand plants. Plants are easily killed by trampling and by vehicles using beaches. In much of its former range it has also suffered from collection of specimens for museums.
Detailed taxonomy
Family
Synonyms
Theleophyton billardierei Moq., Atriplex chrystallina Hook.f.; Obione billardieri Moq.; Theleophyton chrystallina Hook. f.; Theleophyton billardierei Moq.; Obione billardierei Moq.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
November–February
Fruiting
December–April
Life cycle and dispersal
Spongy nutlet dispersed by water and possibly also wind and granivory (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed but difficult to maintain.
Other information
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for March 2023 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
billardierei: Named after Jacques Houttou de Labillardiere (1755-1834), 19th century French botanist who described several New Zealand plants
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.
ATRBIL
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 Endangered | Qualifiers: DP, EF, TO
2012 | At Risk – Relict | Qualifiers: EF, TO
2009 | At Risk – Relict | Qualifiers: EF, TO
2004 | Range Restricted
Referencing and citations
References and further reading
de Lange PJ, Norton DA, Crowcroft GM. 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. https://doi.org/10.1080/0028825X.2000.9512704.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
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 billardierei Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/atriplex-billardierei/ (Date website was queried)