The New Zealand Plant Conservation Network

Species

Myosotis explanata

Etymology

Myosotis: mouse-eared
explanata: Flattened

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 - EF, RR
2009 - DP

Authority

Myosotis explanata Cheeseman

Family

Boraginaceae

Flora Category

Vascular - Native

NVS Species Code

MYOEXP

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None

Distribution

Endemic. South Island: vicinity of Arthurs Pass

Habitat

Riparian in upper montane subalpine to alpine streamsides on rocks or boulders. Akso on cliff faces, rock ledges near waterfalls and in seepages or zones of snow-melt within screes

Features

Stout, tufted, dull green to yellow-green perennial herb. Rosette usually single, leaves obovate to linear-spathulate, 30-70 × 14-16 mm, tip rounded and ± mucronate, petiole nearly as long as lamina, ill-defined; hairs tapering and flexuous, scarcely overlapping, on under-surface shorter, sparser and retrorse. Lateral branches few, erect, up to 200 mm long, internodes < or = leaves. Upper stem-leaves sessile and narrow-elliptic, 15-30 × 5-10 mm, tip broadly acuminate; hairs silky, copious, ± appressed except on fringed margin, shorter and sparser on under-surface. Cymes ebracteate, to 60 mm long, little branched, terminal on primary laterals; internodes between fruits occasionally equal to calyx; pedicels very short. Calyx long, reaching 10 mm in fruit, lobes about half the length of calyx, obtuse, rather broad and keeled; hairs of several lengths, not crowded, a few weakly hooked, spreading or retrorse towards base. Corolla white, up to 10 mm diameter, tube 6-10 mm long, slightly flaring above, lobes flat, rounded, c.4 × 3 mm; filaments very short, fixed just below scales, anthers nearly 2 mm long, tips reaching just beyond large scales; style > calyx in fruit, stigma capitate. Nutlet 2.2-3.2 × 1.2-2.0 mm, ovate to elliptic, black.

Similar Taxa

Myosotis explanata is superficially similar to members of the M. australis agg., M. suavis, and (vegetatively only) the quite unrelated M. macrantha. It shares with the M. australis agg., M. suavis andf M. forsteri calyx hairs of a range of different sizes though with many or all of the longer ones hooked. It differs from members of the M. australis agg. by the larger calyces (up to 10 mm cf. up to 6 mm in the M. australis agg.) with are cut of halfway to the base rather than nearly to the base, by the near absence rather than abundance of hooked hairs on the calyces (some always present), and by the anther scales projecting well above the scales (not in the M. australis agg.). From M. suavis it differs by the sparse rather crowded hair covering of the leaves, and larger (10 mm cf. 7 mm in M. suavis) flower diameter. From Myosotis macrantha there is no reliable way to distinguish vegetative specimens of M. macrantha though the long narrow strongly coloured flowers of M. macrantha with the anthers exserted wholly beyond the ill-developed scales differ greatly from the shorter, salverform, pure white flowers of M. explanata whose anthers are at best only half exserted, and whose filaments are consistently positioned below the large scales.

Flowering

November - January

Flower Colours

White

Fruiting

January - April

Propagation Technique

Like all indigenous Myosotis this species is potentially difficult to cultivate. It is also prone to sudden collapse and a range of fungal diseases. For these reasons it is best grown in an alpine house or rock garden. However, results can be expected to vary across the country and even within the same garden from year to year.

Threats

Myosotis explanata is a narrow-range, naturally uncommon endemic believed to be secure within its only known habitats - most of which fall within a National Park. There are no known threats. However, because there has only been limited observations made of this species in the wild a full survey to ascertain its exact range and abundance would be useful. For this reason the species has been qualified "DP" [Data Poor].

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 16 Apr 2014