minus: small; from the Latin minor
wire rush, lesser wire rush
Current Threat Status
2012 - Not Threatened
Previous Threat Status
2009 - Not Threatened
2004 - Not Threatened
Empodisma minus (Hook.f.) L.A.S.Johnson et D.F.Cutler
Vascular - Native
Calorophus minor Hook.f.; Calorophus elongatus var. minor Hook.f.; Hypolaena lateriflora var. minor (Hook.f.) Cheeseman
Indigenous. New Zealand: North, South and Stewart Islands. From the Central Volcanic Plateau south in upland areas. Throughout the South Island but scarce in Marlborough and north Canterbury. Also Australia.
Coastal to alpine (up to 1350 m a.s.l.). The dominant peat-forming species of low moor and high moor (raised bogs), oligotrophic, ombrotrophic wetland systems in New Zealand (montane to alpine in the North Island). Tolerating extremely acidic conditions (up to pH 2.5).
Dioecious, perennial herb producing numerous, branched, flexuose culms collectively forming densely interwoven tangles. Rhizome rather robust for plant, erect, up to 8 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, 1-1.5 mm diameter, densely covered in pinkish-white root hairs. Culms 0.012-0.81 m, 0.7-1.3 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, 3.5–10.2 mm long, closely appressed to culm, spaced 15-48 mm distant, initially light green to light brown maturing dark brown to brown-black, 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, 1.5-4.2 mm long, initially light green maturing dark brown, fine, sharp-pointed, strongly reflexed. Spikelets distant within uppermost sheaths. Male spikelets 1-2, 3.9-8.0 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 1.2-2.0 mm long, exserted beyond the floral bract. Female spikelets 3.5–7.0 mm long, 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, oval nut, 2.6 mm long, protruding over persistent tepals, sessile on a thick receptacle.
Differs from Empodisma robustum by the 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.
August - December
Main Flower Colour
Other Flower Colour
November - March
Easily grown from seed. Prefers an open, permanently damp, acidic soil but can be grown in dry soils as well. Not often cultivated.
2n = 24
Where To Buy
Not commercially available
The description in Flora II (Moore & Edgar 1970) includes two elements which are now treated as two species Empodisma minus and E. robustum.
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
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: 285-309
This page last updated on 14 Sep 2014