Anisotome acutifolia
Common name
Snares Islands Anisotome
Synonyms
Ligusticum acutifolium Kirk, Aciphylla acutifolia (Kirk) Cockayne
Family
Apiaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Dicotyledonous Herbs other than Composites
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
ANIACU
Current conservation status
The conservation 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). 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.
2012 | Threatened – Nationally Critical | Qualifiers: CD, IE, OL, RR, St
Previous conservation statuses
2009 | At Risk – Naturally Uncommon | Qualifiers: OL, IE
2004 | Range Restricted
Distribution
Endemic. Snares Islands where it is known from North East and Broughton islands.
Habitat
In open ground on margin of dense Olearia lyallii forest, and also recorded from dense Poa foliosa tussock land. Growing semi-shaded sites on deep, permanently damp. peaty soil enriched with bird guano.
Features
Stout, perennial, shortly creeping, stoloniferous herb reaching up to 2 m tall when flowering. Stolons up to 0.3 m long, stout, fleshy, when bruised leaking clear fluid. Basal leaves numerous, coriaceous, 0.50-0.70 m x 0.15-0.20 m, dark green, 2-3-pinnate; primary leaflets in 5-7- pairs, ovate, shortly petiolulate, subcoriaceous., prominently veined; secondary leaflets ovate to lanceolate; pinnately or pinnatifidly divided into deeply toothed and incised segments; teeth acute, not piliferous; petioles 0.2-0.35 m x 4-10 mm, cylindrical; sheaths 40-80 x 25-40 mm, prolonged at apex into an undivided membranous ligule 40-80 mm long; sheaths of cauline leaves inflated; peduncles 90-150 mm long. Inflorescence axis up to 2 m tall and 13 mm diameter at first node. Flowers dirty white to pale pinkish with a slight foetid odour. Staminate plants not described. Pistllate plants bearing an involucre of few linear bracts 6-8 x 1-1.5 mm or not; involucel of several linear bracteoles 7.0-10.0 mm x 0.5-1.0 mm; rays 20-30, 10-25 mm long; pedicels 20-50, 3-5 mm long; styles robust, 0.5-1.0 mm long, divergent. Mericarp 4.0-5.0 x 2.5-3.0 mm long, narrowly elliptic to elliptic, rarely ovate-elliptic, 4.0-4.8(-5.3) mm long; apex and base usually obtuse, sometimes narrow to apex; 5-ribbed, ribs even, equal, thin, narrowly winged with a fine hyaline margin. Surface dull, ribs pale to light orange-yellow, yellow or orange; vittae obscured on dorsal surface, rarely visible, and if so grey brown.
Similar taxa
The only species of Anisotome present on the Snares, A. acutifolia is similar to very large states of A. lyallii Hook.f., and is evidently related to it. The species is distinguished from A. lyallii and indeed all other large indigenous Anisotome by the ligulate leaf sheath (a condition seen otherwise only in the diminutive alpine A. flexuosa J.W. Dawson and A. imbricata (Hook.f.) Cockayne. A similar though less well defined structure is seen in A. antipoda Hook.f. and A. latifolia Hook.f., the two other large subantarctic species. Anisotome acutifolia is poorly known and would repay critical study both taxonomically and also because it is known from so few plants.
Flowering
December -January
Flower colours
Red/Pink, White
Fruiting
January-February
Life cycle
Winged mericarps are dispersed by wind (Thorsen et al., 2009).
Propagation technique
Difficult. Should not be removed from the wild. This species has never been successfully cultivated.
Threats
Believed not to be threatened. However, it is known from only a handful of sites (which may even comprise single plants). It is almost certainly incorrectly listed not because it is actively threatened but rather because the total area of occupancy is believed less than 1 ha. About 1000-3000 mature plants are known but few seedlings have ever been seen, and many of the plants observed could be derived through vegetative spread.
Etymology
anisotome: Unequal sided
acutifolia: With sharp leaves
Where To Buy
Not commercially available
Cultural Use/Importance
A population based genetic study of this species is needed to ascertain how many distinct individuals are. Anisotome acutifolia is in some respects intermediate between A. lyallii and A. latifolia and it may have evolved through past hybridisation between these two species.
Attribution
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013)
References and further reading
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 2009 Vol. 11 No. 4 pp. 285-309
Citation
Please cite as: de Lange, P.J. (Year at time of access): Anisotome acutifolia Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/anisotome-acutifolia/ (Date website was queried)