Species
Pseudognaphalium ephemerum
Etymology
Pseudognaphalium: like Gnaphalium (downy), a related plant
Common Name(s)
kettlehole cudweed
Current Conservation Status
2012 - Threatened - Nationally Critical
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 Critical
2004 - Sparse
Qualifiers
2012 - DP, EF, RR, Sp
2009 - DP, EF, RR, Sp
Authority
Pseudognaphalium ephemerum de Lange
Family
Asteraceae
Flora Category
Vascular - Native
Structural Class
Dicotyledonous Herbs - Composites
Synonyms
Gnaphalium luteoalbum var. compactum Kirk
Distribution
Endemic. New Zealand, South Island, eastern from the upper Wairau River to Southland.
Habitat
Montane to subalpine. Usually in intermontane basins where it is a plant of ephemeral wetlands, kettlehole, tarn and lake margins, strictly in places which are flooded in winter and dry out in summer.
Features
Sparingly to much branched annual herb forming greyish more or less circular patches 10-80 mm diameter, and 10-15 mm tall on dried out mud of montane to alpine lake, pond and tarn beds. All parts densely clad in off white to greyish, floccose, cottony hairs (hairs initially white fading with age to off-white or grey); hairs shedding somewhat on older leaves. Branches filiform, decumbent, apices more or less ascending. Rosette leaves 3-8, mostly all withered at flowering; 7.4-18.6 x 2.0-4.6 mm, obovate, spathulate, oblong-spathulate, oblanceolate, elliptic to linear-lanceolate; apices obtuse to acute, often apiculate, bases cuneate to attentuate, dull grey-green to grey, margins often weakly undulate; mid stem and upper stem leaves 2-3, spreading, up to 10.2 x 1.8 mm, mostly narrow-oblanceolate to spathulate or linear-lanceolate, apices acute to subacute, becoming distinctly smaller near inflorescence, greyish-white to white due to dense hair covering, margins plane. Inflorescence of 1-3 terminal capitula, each subtended by a foliose bract 5.0-8.2 x 2.1-6.3 mm. Capitula mostly solitary, if more than 1 then arranged in very compact, simple, 3-flowered cymes, 2.3-4.3 mm diameter, 2.8-3.8 mm long, outer surface densely invested in white cottony hairs. Involucre narrowly barrel-shaped to urceolate; Involucral bracts arranged in 2-3 rows, basal 1/3 brown to dark brown, otherwise translucent, hyaline, pale amber, somewhat lustrous, weakly oblong, ovate, elliptic to more or less rhomboidal; adaxially with a central tuft of white, cottony hairs otherwise glabrous; outer bracts 4-12, 2.6-3.1 x 1.0-1.2 mm, slightly larger than inner 1-2 rows; inner row 4-8 (third row if present comprising 4-6 bracts). Receptacle 0.68-1.00 mm diameter, very slightly convex, alveolate. Florets 3-6, filiform, 0.9-1.4 mm long, not or scarcely exceeding involucre, corolla pale lemon yellow to almost greenish yellow; female florets 2-4, bisexual 1-2. Cypsela oblong-ellipsoid, more or less terete or compressed, 0.4-0.6 x 0.2-0.3 mm, yellow-orange, surface sparsely invested in papillate hairs. Pappus bristles 9-15, 1.8-2.6 mm long, white, barbellate readily detaching from cypsela
Similar Taxa
Reduced states of Pseudognaphalium luteoalbum which often grow with this species can be similar but these usually have white or buff yellow tomentum, and one or more usually many ascending stems. The stem leaves are broadly to narrowly lanceolate, linear or narrow-spathulate, and typically densely packed along the stems, while the capitula are never solitary and are usually in clusters of 3-10. In New Zealand forms attributed to the northern hemisphere Pseudognaphalium luteoalbum are extremely variable and comprise several potentially undescribed entities. None of those known from the montane and subalpine regions are completely confined to ephemeral wetland habitats that P. ephemerum requires.
Flowering
November - February
Flower Colours
Green,Yellow
Fruiting
December - April
Propagation Technique
Difficult - should not be removed from the wild.
Threats
A biologically sparse, naturally uncommon plant whose occurrences are dictated by the presence of suitable wetland habitats. In some locations, such as Lake Lyndon many thousands of plants can appear in a good season, while at other sites it may be known from year to year by only a handful of specimens. Although its ecological requirements play a strong role in its year to year abundance it cannot be denied that at many of its known locations, especially in the northern South Island it is now seriously threatened by the spread of invasive weeds into its ephemeral wetland habitat.
Chromosome No.
2n = 14
Endemic Taxon
Yes
Endemic Genus
No
Endemic Family
No
Where To Buy
Not commercially available
Notes on taxonomy
Pseudognaphalium ephemerum is a new name and combination for the plant previously known as Gnaphalium luteo-album var. compactum. This plant was transferred to Pseudognaphalium and elevated to species rank by de Lange in de Lange et al. (2010) as a temporary measure to assure its conservation management. Increasingly it is recognised that Pseudognaphalium is probably better placed within Helichrysum, as the defining characters of that genus are shared with Helichrysum.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (28 February 2008). Description by P.J. de Lange based on live plants and herbarium specimens. - this description was subsequently published by 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.
This page last updated on 13 May 2014