Sporadanthus ferrugineus

Common Name(s)

Bamboo Rush, Giant wire rush

Current Conservation Status

2012 - At Risk - Relict

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 - Range Restricted


2009 - CD, De, RR


Sporadanthus ferrugineus de Lange, Heenan, et B.D.Clarkson



Flora Category

Vascular - Native

Structural Class

Rushes and Allied Plants


None (described in 1999)


Endemic. New Zealand: North Island (Waikato - formerly Kaitaia)


Lowland, oligotrophic, high moor, restiad bogs.


Robust, dioecious perennial, 1–6 m high, forming dense rafts. Rhizome 10-15 mm diameter, horizontal, branched. Roots 3–5 × 250-300 mm, white. Culms up to 6 m tall, 10-15 mm diameter, brittle, rigid, upright, terete to subterete, smooth or slightly grooved, glaucous green when young, maturing red-brown or yellow-brown; branched in upper 2/3; branches numerous, slender, firm, flexible, upright; basal 140-200 mm of culm conspicuously swollen with soft, spongy, light brown tissue. Culm base with 3-7 loosely appressed, overlapping scales; scales 10-50 × 15-40 mm, ovate to broadly ovate, coriaceous, light brown to brown, apex rounded and mucronate. Leaves along culm solitary, distant, tightly appressed; lamina 15-50 × 15-50 mm, ovate to broadly ovate, brown to dark brown, fading to grey; basal leaves pectinate, upper leaf margins entire or fractured; apex rounded, mucronate. Inflorescence a terminal panicle up to 150 mm long , red-brown, upright to spreading, sometimes drooping; male inflorescence dense, crowded; female inflorescence sparse, diffuse. Flowers pedicellate to almost sessile. Tepals 6, in 2 whorls of 3, 2.0-3.0 × 0.4-0.5 mm, subulate to lanceolate, light brown to yellow-brown, channelled, apex acute to weakly acuminate, mucronate. Stipe 0.6–0.8 mm long . Male flowers with 3 stamens; filaments 1.8–2 .0 mm long, anthers 1.0-1.3 × 0.2-0.4 mm, cream, pollen yellow; pistil rudimentary. Female flowers with 1 pistil; style 0.8–1 .3 mm long, pink, papillose on upper surface, decurrent with ovary on lower surface; ovary 0.3–0.7 x 0.2–0.6 mm, ± globose, amber to dark brown, vertical groove on upper surface; staminodes 3, each 0.5-0.8 mm long. Fruit 1.2-1.5 × 0.5-0.7 mm, narrowly ellipsoid, sides dark brown, suture light brown to cream-brown, surmounted by persistent, long style; dehiscing along lower suture . Seed 0.7-0.8 × 0.5-0.6 mm, shortly oblong to broadly ovate, light orange-brown when fresh fading to light brown.

Similar Taxa

Distinguished from Sporadanthus traversii by the culms which are 10-15 mm cf. 1-5 mm; tepals not keeled, mucronate, rather than keeled and acuminate, and 2-3 mm cf. 4–6 mm long; by the dehiscent ellipsoid rather than oblong-ellipsoid fruit, 1.0-1.5 mm cf. 3.0-3.5 mm long; and seeds which are 0.7–0.8 × 0.5–0.6 mm cf. 1.2–1.5 × 0.9-1.0 mm long.


October - December

Flower Colours



November - January

Propagation Technique

Easy from seed. Can be grown in most soils but inclined to be rather slow. Resents competition and root disturbance.


Threatened in the past by wetland drainage, which eliminated the species from 95% of its known range by 1970. Today confined toTorehape, Kopouatai and Moanatuatua. Of these Moanatuatua is no longer a truly viable, functioning system and Torehape is being restored, but only Kopouatai truly preserves the Sporadanthus dominated raised bog ecosystem intact. All three populations remain highly vulnerable to fire - itself an issue as there is good evidence that fires are necessary to maintain the species but it is also clear that excessive burning will eliminate it.

Chromosome No.

2n = 18

Endemic Taxon


Endemic Genus


Endemic Family





Fact sheet prepared for NZPCN by P.J. de Lange 18 January 2005. Description adapted from de Lange et al. (1999).

References and further reading

de Lange, P.J.; Heenan, P.B.; Clarkson, B.D.; Clarkson, B.R. 1999: Taxonomy, ecology, and conservation of Sporadanthus (Restionaceae) in New Zealand. New Zealand Journal of Botany 37: 413–431

This page last updated on 6 Dec 2014