Sporadanthus ferrugineus
Common name
bamboo rush, giant wire rush
Synonyms
None (described in 1999)
Family
Restionaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Rushes & Allied Plants
Chromosome number
2n = 18
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | At Risk – Relict | Qualifiers: RR
Previous conservation statuses
2012 | At Risk – Relict
2009 | At Risk – Relict | Qualifiers: CD, De, RR
2004 | Range Restricted
Distribution
Endemic. New Zealand: North Island (Waikato - formerly Kaitaia)
Habitat
Lowland, oligotrophic, high moor, restiad bogs.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Features
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.
Flowering
October - December
Flower colours
Brown, Yellow
Fruiting
November - January
Propagation technique
Easy from seed. Can be grown in most soils but inclined to be rather slow. Resents competition and root disturbance.
Threats
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.
Extra information
Re-creating rare restiad wetlands in the Waikato story in Issue 26 of Trilepidea (November 2006).
Attribution
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
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Sporadanthus ferrugineus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/sporadanthus-ferrugineus/ (Date website was queried)