The New Zealand Plant Conservation Network

Species

Gunnera densiflora

Etymology

Gunnera: Named after Bishop Gunner, a Swedish botanist
densiflora: densely flowered

Common Name(s)

None known

Current Conservation Status

2012 - Threatened - Nationally Endangered

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 - Threatened - Nationally Endangered
2004 - Data Deficient

Qualifiers

2012 - DP
2009 - DP

Authority

Gunnera densiflora Hook.f.

Family

Gunneraceae

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None

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.

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

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.

Chromosome No.

2n = 34

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Fleshy drupes are dispersed by frugivory and possibly ants (Thorsen et al., 2009).

This page last updated on 28 Sep 2014