The New Zealand Plant Conservation Network

Species

Deyeuxia youngii

Etymology

Deyeuxia: after Deyeux

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 - Sparse

Qualifiers

2012 - Sp

Authority

Deyeuxia youngii (Hook.f.) Buchanan

Family

Poaceae

Flora Category

Vascular - Native

NVS Species Code

DEYYOU

Structural Class

Grasses

Synonyms

Agrostis youngii Hook.f., Calamagrostis youngii (Hook.f.) Petrie, Calamagrostis petriei Hack., Deyeuxia petriei (Hack.) Cheeseman, Calamagrostis youngii var. petriei (Hack.) Petrie, Deyeuxia youngii var. petriei (Hack.) Cheeseman,

Distribution

Endemic. South Island only, where it is known from scattered sites from lake Sylvester (North West Nelson) south to Otago

Habitat

Lowland to alpine. In forest clearings, tussock grassland, shrubland, boulderfield, on shaded bluffs, and along lake margins

Features

Slender, tufts .3-1.3 m tall. Leaf-sheath papery, membranous, ribbed, glabrous or finely hairy, light green. Ligule 0.8-2.5 mm, truncate, ciliate to lacerate. Leaf-blade 120-350(-600) x 1-4 mm, stiff, flat or rolled, undersides smooth, upper ribbed, finely scabrid on ribs; margins finely scabrid, apex filiform, acute. Culm 0.4-1.15 m, nodes conspicuous, internodes usually smooth, sometimes scabrid near panicle. Panicle 70-160(-220) x 5-23 mm, linear-lanceolate, shortly and narrowly branched; rachis smooth, branches scabrid, pedicels slightly scabrid. Spikelets 4.5-7.5 mm, light green or purplish, crowded. Glumes 1-nerved, submembranous, elliptic-lanceolate, acute, scabrid, keel scabrid. Lemma (4-)5-6 mm, = glumes, scabrid, elliptic-lanceolate, apex denticulate; awn usually present, (0.5-)1-3 mm, straight, occasionally overtopping lemma apex. Callus hairs fine, covering (1/4)-½ lemma length. Rachilla prolongation 1.5-2.5 mm, surmounted by dense hair-tuft 2-3.5 mm. Anthers penicillate.

Similar Taxa

The narrow, cylindrical panicle place Deyeuxia youngii near D. avenoides (Hook.f.) Buchanan , D quadriseta (Labill.) Benth., and D. lacustris Edgar et Connor. From these species it differs by the callus hairs extending for ½ the lemma length, and by the conspicuous hair tuft of the rachilla prolongation reaching the top of the lemma, or almost so. The lemma and rachilla prolongation characters place D. youngii close to D. aucklandica (Hook.f.) Zotov from which it differs by the linear-lanceolate panicle, lemma 4-6 mm long, and by the straight awn rarely projecting beyond the glumes. In some plants the callus hairs are reduced, but in these cases the short awn and penicillate anthers are distinctive.

Flowering

October - February

Fruiting

October - March

Propagation Technique

Difficult. Dislikes humid climates.Can be grown from the division of whole plants and fresh seed but plants tend to be short-lived

Threats

Naturally uncommon and of sporadic occurrence. In some lowland locations it may be threatened by grassland weeds.

Chromosome No.

2n = 28

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Florets are wind dispersed (Thorsen et al., 2009).

This page last updated on 24 Jul 2014