Poaceae
Triodia

Triodia triaristata Lazarides

First published in Austral. Syst. Bot. 10: 480 (1997)
This species is accepted
The native range of this species is S. Central Northern Territory to N. Central Queensland. It is a perennial and grows primarily in the desert or dry shrubland biome.

Descriptions

Morphology General Habit
Perennial; caespitose; clumped loosely. Butt sheaths distinctly ribbed. Culms 100 cm long. Culm-internodes scaberulous. Leaf-sheaths pubescent; outer margin hairy. Leaf-sheath oral hairs lacking to bearded. Ligule a fringe of hairs; 0.8 mm long. Collar glabrous, or pubescent. Leaf-blades straight, or curved, or flexuous; filiform; conduplicate; 20-45 cm long; 0.8-1.2 mm wide; coriaceous; stiff; resinous. Leaf-blade surface grooved on either side of midline; grooved abaxially.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; oblong; 16-30 cm long; 2.5-5 cm wide. Primary panicle branches simple, or sparsely divided; 6-12 cm long. Panicle axis angular. Panicle branches capillary; without exudate, or resinous. Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; 3-30 mm long.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 7-17 fertile florets; with diminished florets at the apex. Spikelets linear, or lanceolate; laterally compressed, or subterete; 14-27 mm long; 2-4 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes elongated between glumes. Rhachilla elongation 0.5-0.8 mm long. Rhachilla internodes 1-1.5 mm long. Floret callus 0.2 mm long; glabrous; truncate.
Fertile
Spikelets comprising 7-17 fertile florets; with diminished florets at the apex. Spikelets linear, or lanceolate; laterally compressed, or subterete; 14-27 mm long; 2-4 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes elongated between glumes. Rhachilla elongation 0.5-0.8 mm long. Rhachilla internodes 1-1.5 mm long. Floret callus 0.2 mm long; glabrous; truncate.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 5-13 mm long; 1 length of upper glume; scarious, or cartilaginous; without exudate, or resinous; 1-keeled; keeled above; 3 -veined. Lower glume surface smooth, or asperulous. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 1-2 mm long. Upper glume oblong; 5-13 mm long; scarious, or cartilaginous; without exudate, or resinous; 1-keeled; keeled above; 3 -veined. Upper glume surface smooth, or asperulous. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 1-2 mm long.
Morphology Reproductive morphology Flowers Florets
Fertile lemma ovate; 4.5-5 mm long; indurate; much thinner on margins; yellow; without keel; 9 -veined. Lemma lateral veins in close groups. Lemma surface smooth; hirsute; hairy below. Lemma hairs white. Lemma apex lobed; 3 -fid; awned; 3 -awned. Principal lemma awn 3.5-5 mm long overall; limb ciliate; glabrescent towards tip. Lateral lemma awns arising on apex of lobes; 1-3 mm long; shorter than principal; ciliate. Palea oblong, or oblanceolate; 5 mm long; cartilaginous, or indurate; thinner above. Palea keels thickened (at base); winged; narrowly winged; scaberulous. Palea surface scaberulous; pubescent; hairy below. Palea apex dentate; 2 -fid; ciliate. Apical sterile florets resembling fertile though underdeveloped.
Morphology Reproductive morphology Flowers
Lodicules 2; cuneate; 0.8 mm long; fleshy. Anthers 3; 2.5-3 mm long.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp.
Distribution
Australasia: Australia.
Reference
Eragrostideae. Lazarides 1996.
[GB]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • GrassBase - The Online World Grass Flora

    • Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora.
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • World Checklist of Vascular plants (WCVP)

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0