Vascular – Native
Herbs - Dicotyledons other than Composites
2n = c.36
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: DP, RR, Sp
Previous conservation statuses
2009 | Threatened – Nationally Critical | Qualifiers: DP, RR, Sp
2004 | Threatened – Nationally Critical
Endemic. New Zealand: North Island. Formerly recorded from several North Island Hawkes Bay (Allan 1961) localities and at one South Island site near Takaka, North West Nelson. A recent re-circumscription restricts M. petiolata to the eastern North Island where it is known now from only one site in the Te Waka Range, inland Hawkes Bay. Records from East Cape can be attributed to M. pottsiana (Meudt et al. 2013)
Lowland to montane forest. Apparently confined to limestone outcrops and associated soils.
Slender, tufted, bronzed-leaf perennial herb, forming rather open patches up to 1 m. Rosette leaves 8-15(-35) x 10(-25) mm, orbicular, apex apiculate, rarely retuse, borne on long, slender petioles; hairs short, stiff, straight and closely appressed, widely spaced, with longer fringing hairs on sheathing leaf-base. Lateral branches many, rather widely spaced, somewhat trailing, suberect to erect 50-100 mm long, producing offset rosettes; internodes = or > than leaf length. Stem-leaves narrowly oval, upper ones sessile, apiculate, hairs as for rosette leaves. Inflorescence a simple, many-flowered cyme, 40-120 mm long. Calyx 1.5-2(-3) mm, lobes cut almost to base, narrowly acute, spreading in fruit; hairs sparse, short, stiff, like those on leaves. Corolla white, 6-8 mm diam., tube flaring widely, corolla lobes oblong, spreading, scales about level to calyx-tips; filaments long. anthers prominently exserted beyond corolla; style up to 3 x calyx length in fruit. No description of nutlets is known.
M. petiolata is most likely to be confused with M. forsteri, and non-flowering M. spathulata, two species which are superficially similar and can grow in similar habitats. From both M. petiolata can be easily separated by its much larger flowers which have prominently exserted anthers and the often brownish leaf colouration. Field recognition: forming loose brownish coloured patches in which individual rosettes are difficult to distinguish
November - February
Can be grown with difficulty from rooted pieces and fresh seed. Requires specialist knowledge and care to maintain. Tends to be rather short-lived.
Based on herbarium specimens and a preliminary examination of the few wild populations known, M. petiolata would appear to be a biologically sparse entity favouring base-rich substrates. Because there are few plants known from the wild, little is known about this plants ecology, and it may be vulnerable to weed invasions it is currently classified as Nationally Critical.
petiolata: Having leaf-stalks
South Island plants referred to Myosotis petiolata do not appear to be closely related to either M. petiolata s.s. (Meudt et al. 2013).
Fact Sheet prepared by NZPCN by P.J. de Lange 1 February 2008. Description subsequently published in de Lange et al. (2010). For a more recent assessment see Meudt et al. (2013).
References and further reading
Allan, H.H. 1961: Flora of New Zealand. Vol. I. Goverment Printer, Wellington.
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.
Meudt, H.M.; Prebble, J.M.; Stanley, R.J.; Thorsen, M.J. 2013: Morphological and amplified fragment length polymorphism (AFLP) data show that New Zealand endemic Myosotis petiolata
(Boraginaceae) comprises three rare and threatened species. Australian Systematic Botany 26: 210-232.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Myosotis petiolata Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/myosotis-petiolata/ (Date website was queried)