Gunnera densiflora
Synonyms
None
Family
Gunneraceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
Chromosome number
2n = 34
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 | Threatened – Nationally Endangered | Qualifiers: DP
Previous conservation statuses
2012 | Threatened – Nationally Endangered | Qualifiers: DP
2009 | Threatened – Nationally Endangered | Qualifiers: DP
2004 | Data Deficient
Distribution
Endemic. Known only from the eastern side of the South Island from the inland Kaikoura Range west to Lake Tennyson, and south to the Craigieburn Range.
Habitat
A species of montane lake margins and stream sides.
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).
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Features
Creeping, stoloniferous, Dioecious, herb forming compact cushions. Stolons much branched, partially buried, fleshy, succulent, up to 3 m long, 1.9–3.1 mm diameter, internodes 30–50 mm long, exposed parts pinkish-red, pink or greenish-red, densely clad in wispy, cob-webbed silky hairs. Leaves in compact, moderately tight, leafy overlapping rosettes; petioles stout, succulent, ± winged, 10–30 × 1.5–2.4 mm, pink, pinkish-red, or greenish-red, concave, ± channelled, and sparsely silky hairy above, glabrate to glabrous below, wider at base, slightly widening toward cuneate leaf base, lamina membranous to subcoriaceous, 10–46 × 15–38 mm, obovate, broadly obovate, ovate to oblong, elliptic to suborbicular, apex sub-acute to acute, cuneate, truncate to subcordate at base, round at apex, margins mostly crenate-crenulate, (rarely slightly sinuate), usually dentate near base, teeth ovate , oblong, obtuse, or acute, 0.8–1.8 mm, initially apiculate, apiculus caducous, green to dark green, sometimes mottled or flushed pink, upper and lower surface glabrate to glabrous, hairs sparse, mostly confined to midrib and veins in lower ¼ of lamina. Inflorescence an ebracteate, erect, fleshy, stout, spike up to 70 mm tall in male, 30 mm in female, located within leaf axils, peduncle and rachis silky hairy, hairs often matted: flowers 12–40 (or more) spiralled, widely spaced to ± crowded, glabrous, proximal flowers pedicellate grading through to sessile in distal portion; calyx lobes 0–2 (mostly present in distal portion of spike), lobes 0.9–2.5 × 0.4–1.2 mm, equal, linear-lanceolate, lanceolate to spathulate, subentire or dentate, glabrous; sepals much reduced or absent, 0.1–0.2 × 0.01–0.1 mm, oblong, glabrous, caducous, petals similar; male flowers: stamens 1–2, subsessile to sessile, filaments 0.2–0.9 mm, anthers pale yellow, gynoecium rudimentary; female flowers similar to male, stamens reduced to staminodes or absent, ovary 0.2–0.4 × 0.1–0.2 mm, urceolate, greenish-white, hyaline, glabrous, styles 2, prominent, widely spreading, 1.0–3.2 mm, subulate-filiform; stigmas papillate . Fruiting spike erect, up to 30 mm long; drupes widely spaced to densely clustered, fleshy, pendulous, 2.8–3.2 mm, obconic, pyriform or clavate, dark red. Endocarp 1.3–2.6 mm, oblong-elliptic, elliptic, dull orange-yellow, yellow or orange-brown, ± smooth.
Similar taxa
A distinct species, perhaps closest to G. prorepens but distinguished from it and all other indigenous Gunnera species by the coarsely dentate, broadly-ovate heart-shaped leaves, and dense fruiting stems.
Flowering
September–December
Flower colours
Yellow
Fruiting
November–March
Life cycle
Fleshy drupes are dispersed by frugivory and possibly ants (Thorsen et al., 2009).
Propagation technique
Very easy from rooted pieces and divisions of whole plants. Fresh seed germinates easily. Grows best in damp, sunny conditions.
Threats
It would appear that Gunnera densiflora has never been very common. This attribute, along with the fact that large parts of its intermontane basin habitat has been overrun by weeds, means that the species is probably threatened. However, because so populations are known, and because the species appears to be very variable throughout its range, an exact and confident conservation assessment is unlikely without further field surveys.
Etymology
gunnera: Named after Bishop Gunner, a Swedish botanist
densiflora: Densely flowered
Attribution
Fact Sheet Prepared by P.J. de Lange (1 November 2009). Description by P.J. de Lange subsequently published in de Lange et al (2010).
References and further reading
de Lange, P.J.; Heenan, P.B.; Norton, D.A.; Rolfe, J.R.; Sawyer, J.W.D. 2010: Threatened Plants of New Zealand. Canterbury University Press, Christchurch.
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
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Gunnera densiflora Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/gunnera-densiflora/ (Date website was queried)