Libertia cranwelliae
Common names
Cranwell’s iris, Cranwell’s mikoikoi
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Monocots
Detailed description
Plants consisting of leafy fans crowded or emerging at intervals from far-spreading horizontal stolons; stolons c. 3–5 mm diameter, bright yellow. Leaves 150–900 mm × 5–11 mm, the two surfaces similar; inclined to turn yellow where exposed to full sun; leaf bases yellow; nerves many, median ones crowded to form a midrib; margins not scabrid, leaf in transverse section convex lens-shaped, two rows of vascular bundles present, marginal vascular bundles present, sclerenchyma present on inside of leaf sheath. Peduncles long (2/3 the length of inflorescence) but inflorescences short (2/3 the length of the leaves), flowers and fruits not reaching top of leaves. Panicle narrow, sparsely branched; lower bracts long (180–250 mm), lanceolate and orange-green, upper bracts smaller and membranous brown, occurring singly; 1–3 flowers per branch. Pedicels stout, 5–16 mm long, glabrous. Flower bud sometimes yellowish or brown, usually similar size to ovary sometimes smaller, flowers 20–35 mm diameter; tepals all white internally, widely patent; outer tepals usually > ½ the length of the inner, narrower, elliptical, flattened, with an apiculus; inner tepals oval-elliptical, shortly unguiculate, not usually covering outer tepals, cleft at tip. Staminal filaments very shortly connate; anthers c. 3 mm long, yellow. Ovary yellowish green, ribbed cupiform, greater than or equal to perianth bud; style branches not winged, pointing outwards. Capsule large, up to 20 mm long, barrel-shaped, ripening from green to yellow-orange to black or grey-black, ± indehiscent, apex sometimes spliting slightly. Seeds dispersed when capsule disintegrates. Seeds c.1.5 ×1.5 mm, globose to angular, orange-brown in colour.
Similar taxa
Libertia cranwelliae is most similar to L. ixioides from which it is distinguished by the wide spreading, elongate, yellow stolons, leafy fans spreading some distance from parent plant, and leaves with inconspicuous venation. According to Blanchon et al. (2002) it is reproductively isolated from both L. ixioides or L. grandiflora. Plants are further distinguished from all other New Zealand Libertia by their 5S rDNA, and cpDNA (trnL-trnF) sequence.
Distribution
Endemic. New Zealand: North Island (East Cape from near Hicks Bay south to the Kopuapounamu valley)
Habitat
Coastal forest on cliff faces, in seepages, on stream and river banks.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Threatened – Nationally Critical | Qualifiers: DPT, OL
Threats
Recently (2006) rediscovered in the wild by Graeme Atkins at one site near East Cape where there are c.30 plants growing in coastal forest. This site is threatened by weeds, goats, cattle and red deer. Libertia cranwelliae has not been rediscovered at its former locations at the Awatere River and Kopuapounamu Valley.
Detailed taxonomy
Family
Synonyms
None (first described in 2002)
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
September - November
Fruiting
January - December
Life cycle and dispersal
Seeds are possibly dispersed by wind (Thorsen et al., 2009).
Propagation technique
Easily grown by division of whole plants. Fresh seed germinates readily.
Other information
Etymology
libertia: Named after Marie-Anne Libert, (1782-1865) born & died in Malmedy, province of Liège, Belgium; botanist and mycologist
Chromosome number
2n = 228
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Critical | Qualifiers: DP, OL
2012 | Threatened – Nationally Critical | Qualifiers: DP
2009 | Threatened – Nationally Critical | Qualifiers: DP
2004 | Data Deficient
Referencing and citations
References and further reading
Blanchon, D.J.; Murray, B.G.; Braggins, J.E. 2002: A taxonomic revision of Libertia (Iridaceae) in New Zealand. New Zealand Journal of Botany 40: 437–456.
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
Attribution
Description modified from: Blanchon et al. (2002)