Classification
Class
Magnoliopsida Brongn.
Order
Poales Small
Family
Gramineae Juss.
Genus
Rytidosperma Steud.
 Nomenclature
Scientific Name:
Rytidosperma thomsonii (Buchanan) Connor & Edgar, New Zealand J. Bot. 17: 322 (1979)
Synonymy:
  • ≡ Danthonia thomsonii Buchanan, Indig. Grasses of N. Z. t. 36 (2) (1879)
  • ≡ Triodia thomsonii (Buchanan) Petrie (1912)
  • ≡ Notodanthonia thomsonii (Buchanan) Zotov, New Zealand J. Bot. 1: 112 (1963)
 Description

Variable in size and habit, from low-growing tussocks to moderately tall tufts, rather dull green, ± shortly rhizomatous; leaves semi-pungent, usually » culms; branching intravaginal, shoots crowded, ± swollen at base. Leaf-sheath pale to greyish, glabrous, sometimes with scattered long hairs; apical tuft of hairs 1–3 mm. Ligule c. 0.3 mm. Leaf-blade to 15–(22) cm, stiff, inrolled with scabrid margins, glabrous, or with scattered long hairs. Culm to 45 cm, internodes smooth but minutely scabrid below inflorescence. Panicle strict, to 6.5 cm, shortly branched below, of few to many spikelets on short pedicels; rachis and pedicels closely short-scabrid, with numerous minute hairs interspersed, longer hairs below spikelets and at branch axils. Spikelets 5–8-flowered, sometimes upper florets exceeding glumes. Glumes purplish centrally, ovate-lanceolate, subacute, (3.5)–5–7–(9) mm, ± equal; lower 5–(7)-nerved, upper 3–(5)-nerved. Lemma 2.5–3.5–(4) mm, finely 7–(9)-nerved, both rows of hairs reduced to short dense marginal tufts, elsewhere glabrous, upper hairs < lemma lobes; lobes reduced to minute bristles, 0.1–0.4–(0.6) mm, rarely almost wanting; central awn (0.2)–0.5–1–(2.5) mm, straight, erect, fine, or reduced to a mucro from a bifid lemma-tip, column absent. Palea 2.3–3 mm, ≤ base of sinus, » upper lemma hairs, interkeel and margins glabrous. Callus 0.2–0.3 mm, thick marginal hair tufts reaching base of lower marginal lemma tufts. Rachilla c. 0.5 mm. Anthers 0.4–0.7 mm. Caryopsis 1–1.3 × 0.4–0.7 mm; embryo to 0.5 mm; hilum c. 0.2 mm. Plate 12G.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 (second printing).]

 Biostatus
Indigenous (Endemic)
 Bibliography
Buchanan, J. 1878: The Indigenous Grasses of New Zealand. Vol. Part I & II. Wellington, N.Z.
Connor, H. E.; Edgar, E. 1979: Rytidosperma Steudel (Notodanthonia Zotov) in New Zealand. New Zealand Journal of Botany 17: 311–337.
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61–96. [Data deficient]
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series. No. 22. [Declining]
de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington. [Data Deficient]
Zotov, V.D. 1963: Synopsis of the grass subfamily Arundinoideae in New Zealand. New Zealand Journal of Botany 1: 78–136.