The New Zealand Plant Conservation Network

Species

Myosotis arnoldii

Etymology

Myosotis: mouse-eared

Common Name(s)

None Known

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - At Risk - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - RR

Authority

Myosotis arnoldii L.B.Moore

Family

Boraginaceae

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None (first described in 1961)

Distribution

Endemic. South Island: Marlborough (Upper Ure (Waima) River, Chalk Range especially around Ben More; Nelson (Hoary Head)

Habitat

Myosotis arnoldii is a basicole known only from marble (North West Nelson) and limestone (Marlborough) rocks where it grows on sparsely vegetated cliff faces, ledges and associated rubble slopes.

Features

Stout, tufted, silvery grey perennial herb. Rosette-leaves 30-70 × 5-9 mm, linear-spathulate to oblanceolate, lamina merging into broad ill-defined petiole, tip subacute to obtuse; hairs alike on both surfaces, uniformly stiff, straight, closely appressed, strongly overlapping so at to completely cover leaf surface. Lateral branches erect, up to 180 mm long, leafless below cyme, lower internodes < leaves. Stem-leaves 15-25 × 2-5 mm, narrow-oblong, tip subacute; hairs like those of rosette-leaves. Cymes usually once forked, ebracteate, many-flowered, compact and 2-3 cm. long in flower, internodes and pedicels short. Calyx c.8 mm long, lobes c. 1/2 length, subacute; covered in short appressed hairs, these forming a close even silvery cover from which project long stiff hooked hairs that are most numerous towards the base. Corolla yellow, greenish to almost black, 8-10 mm diameter, tube 10-15 mm long, narrow-funnelform, > lobes, lobes c.3 × 3 mm, ± oblong; filaments broad, fixed between scales, about equal to anthers; anthers 2 mm long, wholly above scales; style at least 2× calyx, stigma capitate. Nutlet 2.6-3.1 × 1.3-1.5 mm, ovate-elliptic to elliptic, black.

Similar Taxa

Myosotis arnoldii is like a stouter version of M. angustata from which it differs by its silvery leaves and stems, strongly overlapping leaf hairs which completely obscure the leaf epidermis, and by the typically dark greenish to almost black (rarely yellow) rather than white flowers. The flowers of Myosotis arnoldii are rather similar to those of M. macrantha which can show the same range of colours, they differ only in that the lobes of M. macrantha seem to spread more widely.

Flowering

October - January

Flower Colours

Green,Yellow

Fruiting

December - May

Propagation Technique

Somewhat difficult. Can be grown in a rock garden or alpine house but results vary. Like all indigenous Myosotis this species is sensitive to humidity and prone to fungal attacks from mildews and rusts in muggy weather.

Threats

Within its only known habitat this species is locally common and so far does not appear to be seriously threatened by weeds or browsing animals.

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 16 Apr 2014