The New Zealand Plant Conservation Network

Species

Empodisma robustum

Etymology

Empodisma: Tangle-foot
robustum: sturdy

Common Name(s)

wire rush

Current Conservation Status

2018 - At Risk - Declining

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

2012 - Not Threatened
2009 - Not Threatened

Authority

Empodisma robustum Wagstaff et B.R. Clarkson

Family

Restionaceae

Flora Category

Vascular - Native

NVS Species Code

EMPROB

Structural Class

Monocotyledonous Herbs

Synonyms

None first described in 2012

Distribution

Endemic. New Zealand: North Island (Te Aupouri Peninsula south to the lower Waikato).

Habitat

Empodisma robustum is restricted to ombrotrophic raised peat bogs where it often coexists with Sporadanthus ferrugineus, fens and gumland heathland peats. It is often locally abundant.

Features

Dioecious, perennial herb producing numerous, branched, flexuose culms collectively forming densely interwoven tangles. Rhizome rather robust for plant, erect, up to 12 mm diameter, covering with light brown, imbricating scale-like sheaths and very thick tufts of brown hairs; roots numerous, mostly horizontal-ascending rather than descending, 1.2-1.8 mm diameter, densely covered in pinkish-white root hairs. Culms 0.38-2.2 m, 0.9-2.2 mm diameter, much-branched, flexuous, terete or slightly flattened and grooved on one side, glabrous, dark green to dark brown, erect when short, otherwise more or less prostrate to ascending, widely spreading and lianoid. Leaves reduced to mucronate sheaths, 5.2–21.0 mm long, closely appressed to culm, spaced 20-70 mm apart, initially light green to light brown maturing dark brown, margin entire; cilia protruding through the mouth of the sheath as white tufts of woolly white hairs; hairs arising from the outer scale of the axillary bud enclosed within sheath; mucro persistent, 2.2-7.5 mm long, initially light green maturing dark brown, fine, sharp-pointed (accicular), strongly reflexed from leaf sheath. Spikelets brown, distant within uppermost sheaths. Male spikelets 1-2, 6.8-9.0 mm long, 1-6-flowered, 1 sessile and 1 stalked, each borne within a hard, mucronate sheath; tepals 6, narrow-linear, acute; stamens 3, filaments slender, > tepals, anthers 1.9–2.5 m, exserted beyond the floral bract. Female spikelets 5.8–8.9 mm, solitary within 1-3 uppermost, bearded, obtuse sheaths, 1-flowered, subtended by 2 imbricate, empty floral bracts; tepals 6-4, very small, hyaline; styles 3, free. Fruit a hard nut, 2.7 mm long, dark brown, ovoid, protruding over persistent tepals, sessile on a thick receptacle.

Similar Taxa

Empodisma minus differs from E. robustum by its diminutive stature and slender growth habit; culms mostly < 1 mm in diameter, sheaths mostly < 7.5 mm long and spikelets generally < 6.0 mm long. Readily distinguished from the two other New Zealand restiad genera Sporadanthus and Apodasmia by the mostly widely spreading, decumbent, trailing to lianoid growth habit, and 1-6-flowered male and 1-flowered female spikelets.

Flowering

August - October

Flower Colours

Yellow

Fruiting

November - March

Propagation Technique

Easily grown from fresh seed and by the division of established plants. Despite its natural restriction to acidic wetlands. Empodisma robustum can be easily grown in a range of media though it does best in full sun in a permanently damp soil.

Threats

Not Threatened

Chromosome No.

2n = 24

Endemic Taxon

No

Endemic Genus

Yes

Endemic Family

No

This page last updated on 20 Oct 2014