Species

Atriplex australasica

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
australasica: Of or from Australasia

Common Name(s)

Orache, saltbush

Current Conservation Status

2012 - At Risk - Naturally Uncommon

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - At Risk - Relict
2004 - Non Resident Native - Vagrant

Qualifiers

2012 - RR, SO
2009 - SO, RR

Authority

Atriplex australasica Moq.

Family

Amaranthaceae

Flora Category

Vascular - Native

NVS Species Code

ATRAUS

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.

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Atriplex patula var. gunnii Aellen, A. patula var. serratifolia Aellen

Distribution

Indigenous. Known in the South Island from a 1770 collection from the Marlborough Sounds, possibly from two 1860 collections made from south Canterbury by Haast and Kirk. However the species is abundant on the Chatham Islands. Also indigenous to the southern coast of Australia and Tasmania.

Habitat

Strictly coastal. On the Chatham Islands it is usually found in open habitats such as along sand, shell, cobble or boulder beaches bordering the lagoon, on clay banks and cliff faces throughout the main island, particularly where near shag roosts, and commonly amongst sea-bird colonies and seal haul outs.

Features

Annual much-branched, grey-green, glaucous to red-green, monoecious (?gynodioecious) shrub up to 1 x 2 m. Main stems quadrangular, widely spreading to sub-erect, woody at base, otherwise firmly fleshy to succulent; deeply ribbed, stout up to 15 mm diameter, grey-green to glaucous at first becoming purple-red to maroon with age. Upper stems similar, though much branched, ribbed and more or less slender. Petioles stout, fleshy up to 20 mm long. Leaves 20-100 x 30-60 mm, grey-green, glaucous to red-green, very fleshy to almost succulent, broadly lanceolate, broadly-deltoid to broadly hastate, lamina of young plants more or less entire, usually with 1-2 deep forward projected lobes near base, these often present on one side, mature leaves entire or deeply though irregularly lobed to almost coarsely dentate, lobes broadly deltoid blunt ended, forward projecting; leaf-base broadly cuneate; apex obtuse, sub-obtuse to acute. Inflorescence leaves similar though smaller. Inflorescence long, spiciform, paniculate more or less arching and pendulous at fruiting. Flowers in dense glomerules, these at first continuous, become disjunct; upper glomerules usually subtended by small bract-like leaves. Male flowers with perianths 0.5-1 mm long; segments green with fine hyaline margin. Female flowers enclosed by bracteoles 1.5-1.8(-2) mm long at anthesis, sessile, rhombic-triangular to triangular hastate, usually entire, sometimes toothed or with protuberances. Fruiting bracteoles 3-4 x 2-5 mm, deltoid, fused near base, equal to subequal, entire or with 1-2 teeth, smooth or with warty protuberances, very fleshy, grey-green to glaucous at first becoming black and much-thickened with age, apices acute. Fruits dimorphic, enclosed within bracteoles, mostly 2.5-4 mm diameter, orbicular, laterally flattened, radicle basal, horizontal; pericarp loose, chartaceous often ruptured at fruit maturation. Testa glossy black, smooth.

Similar Taxa

Atriplex patula L. with which it has been confused in New Zealand literature. It should be noted that many botanists regard both species as the same, in which case A. patula has priority. From A. patula s.s., A. australasica differs consistently by its much wider, often deeply toothed or lobed leaves. In immature or juvenile plants the leaves are often entire or lobed 1-2 times near the base. However, from the typical form of A. patula seen in New Zealand, A. australascia differs by its more robust stature and much more fleshy-glaucous foliage.

Flowering

November - April

Flower Colours

Green

Fruiting

December - May

Propagation Technique

Unknown. However probably easily grown from fresh seed and semi-hardwood cuttings.

Threats

Uncertain. Only recently rediscovered on the Chatham Islands where it is very common.

Chromosome No.

2n = 36-38

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Spongy nutlet dispersed by water and possibly also wind and granivory (Thorsen et al., 2009).

Where to Buy

Not commerciailly available.
 

Attribution

Fact sheet and description prepared for the NZPCN by P.J. de Lange July 2007

References and further reading

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 2009 Vol. 11 No. 4 pp. 285-309

This page last updated on 10 May 2014