kopakopa, Chatham Island forget-me-not, kopukapuka
Myosotis hortensia Decne, Cynoglossum nobile Hook.f., Myosotidium nobile (Hook.f.) Hook.f.; Myosotidium hortensium (Decne.) Baill. orth.var.
Vascular – Native
Herbs - Dicotyledons other than Composites
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.
2n = 40-42
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 Vulnerable | Qualifiers: CD, IE
Previous conservation statuses
2009 | Threatened – Nationally Vulnerable | Qualifiers: CD, IE, Inc, RR
2004 | Threatened – Nationally Endangered
Endemic to the Chatham Islands. Found on Chatham (Rekohu), Pitt, South East, Mangere and most of the smaller islands, islets and some rock stacks.
Coastal cliffs, rock outcrops, sandy and rocky beaches just above the strand zone and coastal forest openings.
Robust, perennial herb, forming patches up to 1 m tall by 1.0–1.5 m diameter. Root stock stout, cylindric, rather fleshy, where emergent covered in numerous leaf scars, becoming woody with age. Petioles 0.1–0.5 m long, grooved above, channelled below. Lamina of basal leaves up to 0.4 m across, dark green to yellow-green, broadly ovate-cordate to reniform, thick, fleshy to coriaceous; upper surface glossy, glabrous; lower surface paler, minutely and evenly covered in retrorse hairs; margins entire; veins prominent, indented above, elevated below. Inflorescences lateral corymbose cymes, somewhat woody at base, with stem leaves; lower stem leaves similar to basal leaves, upper stem leaves smaller, oblong to broadly lanceolate or elliptic. Cymes 100–200 mm diameter, pedicels 10–15 mm long. Calyx lobes 5, 1.8–4.5 × 2.0–2.5 mm, broadly elliptic, covered in appressed hairs, apex obtuse, margin entire. Corolla 12–15 mm diameter, dark blue to pale blue, often flushing purple with age, occasionally white; lobes 5, 4.0–4.5 × 5.0–6.0 mm, orbicular, rounded, spreading, overlapping, apex obtuse; tube 2 mm long, throat partially occluded by 5 fleshy protuberances. Filaments c. 0.5 mm long, inserted near throat; anther included, 1.0–1.2 mm long. Ovary 4-lobed, style 0.7–1.0 mm long, stigma capitate. Fruit a nutlet, 10–15 mm diameter, brown to black, winged around margin; seed obovate, 7.5–9.0 mm long, testa black-brown.
A distinctive and easily recognised species with large, glossy green leaves and large blue-flowered inflorescences.
September - November
October - May
Easy to grow provided the root stock is kept moist. It will not tolerate drought. It also dislikes humidity. Does best in a rich, well fertilised, peaty soil on the south-side of a building, or near a dripping tap. Also does well in partial shade under trees. Avoid competition from other plants. Seed germinates well if fresh but will not store long. A white-flowered form is occasionally grown.
Formerly abundant around the coasts and islets, the range of Myosotidium hortensium has been significantly reduced to scattered remnants by farming, competition from marram grass (Ammophila arenaria) and the depredations of feral animals, such as cattle, horses, sheep, possums, pigs, rats and weka who trample, uproot and browse plants. Possums, rodents, and weka are serious predators of flowers and fruits. Weed encroachment, especially by marram grass, has eliminated this species from most of its former dune habitat. Removing whole plants for private use in gardens is an ongoing problem for the more accessible populations. Coastal development destroyed the only known white-flowered wild plants, and remains a potential threat elsewhere.
Where To Buy
Commonly available from most commercial and specialist native plant nurseries.
Fact Sheet prepared for NZPCN by P.J. de Lange 1 February 2008. Description based on 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.
Garnock-Jones PJ. 2014: Evidence-based review of the taxonomic status of New Zealand’s endemic seed plant genera, New Zealand Journal of Botany, DOI: 10.1080/0028825X.2014.902854
Heenan, P.B., Schönberger, I. 2009. Typification of Myosotis hortensia Decne., the basionym of Myosotidium hortensium (Decne.) Baill., and its synonym Cynoglossum nobile Hook.f. (Boraginaceae). New Zealand Journal of Botany, Vol. 47: 121–125
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Myosotidium hortensia Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/myosotidium-hortensia/ (Date website was queried)