The New Zealand Plant Conservation Network

Species

Australopyrum calcis subsp. calcis

Common Name(s)

limestone wheatgrass

Current Conservation Status

2012 - Threatened - Nationally Endangered

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 - Threatened - Nationally Endangered
2004 - Threatened - Nationally Endangered

Qualifiers

2012 - CD, OL, St
2009 - CD, St, OL

Authority

Australopyrum calcis Connor et Molloy subsp. calcis

Family

Poaceae

Flora Category

Vascular - Native

NVS Species Code

AUSCSC

Structural Class

Grasses

Synonyms

None

Distribution

Endemic. New Zealand, South Island, Marlborough. Known only from two sites in the Leatham Valley.

Habitat

Apparently a limestone endemic. The only known population grows mainly near a limestone outcrop in shaded sites under trees on lime-rich soils and limestone debris. However a very few plants grow directly on the limestone outcrop under shaded rock overhangs and ledges.

Features

Stout, stoloniferous red-green to dark green perennial grass. Leaf-sheath 25-50 mm, with retrorse short hairs, reddish green. Auricles 0.1-0.5 mm. Ligule 0.6-1.25 mm, lacerate. Collar dark brown to purple. Leaf-blade 60-250 x 0.5-3.5 mm, flat, thin, upper surface with minute prickle-teeth on ribs; underside with conspicuous white midrib and 2 lateral ribs. Culm 170-600 mm, slender, reddish, nodes swollen, dark-brown to black. Inflorescence a spicate raceme 30-130 mm; spikelets 4-13, overlapping; rachis internodes glabrous, margins toothed. Spikelets 10-14 mm. Glumes unequal, lower 2.5-4 mm, upper 3.7-5.5 mm, narrowly to broadly-triangular, 3-5-nerved, undersides prickle toothed, upper invested with short white hairs. Lemma 9-11 m; undersides with stiff 0.1 mm long teeth, awn 1.5-4 mm. Palea 5.3-7 mm, apex bidid. Callus 0.25-0.4 mm upperside with short stiff hairs. Anthers 2.4-2.8 mm. Ovary 0.8-1 mm, stigma-styles 1.8-2 mm. Seed 3.5-4 mm, linear.

Similar Taxa

Australopyrum calcis subsp. optatum Connor et Molloy is a smaller and more slender grass. The upper surfaces of the leaves of this subspecies are distinctly, though finely, hairy (glabrous in subsp. calcis), while the culm internodes are glabrous except for the last internodes below the inflorescence which is finely hairy (glabrous in subsp. calcis). In this subspecies the inflorescence rachis is finely hairy while that of subsp. calcis is glabrous.

Flowering

December - January

Fruiting

December - May

Propagation Technique

Very easy from fresh seed. Does best in a pot. Can be grown in full sun or shade. Dislikes high humidity. Plants respond well to regularly applications of lime.

Threats

Known from two extremely restricted sites in the Leatham Valley, South Marlborough. It is estimated that less than 200 plants are known from two sites in close proximity. The main population occurs at the base of a limestone bluff, while the other occurs along an old vehicle track at an adjacent limestone quarry. These populations are protected but are very vulnerable summer drought which can stress and even kill the overlying trees, thereby opening up the habitat to weeds. Although the grass is not especially palatable it is occasionally browsed by rabbits and hares.

Chromosome No.

2n = 14

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 27 Aug 2013