The New Zealand Plant Conservation Network

Species

Rytidosperma merum

Etymology

Rytidosperma: wrinkled seed

Current Conservation Status

2018 - At Risk - Declining

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

2012 - Threatened - Nationally Vulnerable
2009 - Data Deficient
2004 - Sparse

Qualifiers

2012 - DP, Sp
2009 - DP

Authority

Rytidosperma merum Connor et Edgar

Family

Poaceae

Flora Category

Vascular - Native

NVS Species Code

RYTMER

Structural Class

Grasses

Synonyms

Austrodanthonia mera (Connor et Edgar) H.P.Linder

Distribution

Endemic. North Island, Kaingaroa Plains and Kaimanawa Mountains, eastern Wairarapa and Aorangi Range. South Island, Marlborough, Canterbury, near Alexandra and Sutton Salt Lakes, Middlemarch (Otago).

Habitat

Lowland to montane (100-800 m a.s.l.) in dry sites, usually in open short-tussock grassland but also on rock outcrops.

Features

Rather fine-leaved, densely tufted, light green, shortly rhizomatous grass. Older growth distinctly straw-coloured, with long, drooping or trailing culms; leaves very much less than culms; branching extra or intervaginal. Leaf-sheath pale stramineous, glabrous with a sparse apical tuft of hairs up to 1.5 mm long. Ligule 0.1-0.2 mm. Leaf-blade 250-400 mm, more or less flat, glabrous, occasionally with a few sparse, scattered hairs, margins scabird. Culm very slender, tawny with smooth internodes otherwise minutely scabrid belwo inflorescence, elongating to 0.14 m (or more) at maturity, Raceme or racemose panicle with 1-2 short branches at base, slender to 80 mm, comprising few narrow, sessile to subsessile spikelets; rachise and pedicels finely scabrid with longer fine hairs on margins especially below spikeletes. Spikelets 4-6-flowered, awns exserted from glumes. Glumes light green, occasionally purplish, lanceolate, subobtuse 7-15 mm, more or less equal, 5-7-nerved. Lemma 2.5-4 mm, 7-9-nerved, upper row of hairs in small marginal tufts only, about equal to lemma or occasionally with upper tufts absent, lower row in small marginal tufts only, or a few small tufts or single hairs on margin; lobes 3-8.5 mm, soon tapering to a fine awn; central awn 6.5-14 mm, column 2.5-3.5 mm. Palea 2.5-5 mm, > upper lemma hairs, interkeel and margins glabrous. Callus 0.6-1 mm, marginal hair tufts rarely reaching base of lower lateral tufts. Rachilla 0.5-0.6 mm. Anthers 0.3-1.5 mm. Seed 1.7-2.5 x 0.9-1.2 mm.

Similar Taxa

One of the more distinctive species in Rytidosperma. Most frequently confused with the naturalised R. racemosum (R.Br.) Connor et Edgar from which it differs by the much shorter leaves than culms, finer leaves, long, drooping and trailing culms, and by the lemma hairs in two pairs of marginal tufts, rarely with a few single hairs in a lower row, and by the short, stout, callus up to 1 mm long. In R. racemosum the lemma hairs form a continuous lower row, and an interrupted, tufted, upper row, and the callus is long (up to 1.5 mm) and distinctly narrower than in R. merum.

Flowering

October - December

Fruiting

November - April

Propagation Technique

Easily grown from fresh seed and rooted pieces. Dislikes humidity.

Threats

Not known to be threatened but apparently very uncommon throughout its range. Can be very common at the few sites it is known from

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 17 Jan 2014