Poaceae
Arthraxon

Arthraxon junnarensis S.K.Jain & Hemadri

First published in J. Bombay Nat. Hist. Soc. 68: 300 (1971)
This species is accepted
The native range of this species is Oman, India, China (W. Yunnan). It is an annual and grows primarily in the seasonally dry tropical biome.

Descriptions

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: low confidence
[AERP]

Morphology General Habit
Annual. Culms rambling; weak; 10-20 cm long; rooting from lower nodes. Culm-nodes pubescent. Leaf-sheaths 0.5-1.75 cm long; pilose; with tubercle-based hairs. Ligule a ciliolate membrane; 0.7 mm long. Leaf-blade base broadly rounded. Leaf-blades lanceolate, or ovate; 1-2.5 cm long; 5-7.5 mm wide. Leaf-blade surface pilose; with tubercle-based hairs.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Peduncle 2-3 cm long; glabrous. Racemes 5-12; digitate; 1-1.75 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform; 1.25-1.8 mm long. Spikelets solitary. Fertile spikelets sessile. Pedicels filiform; 0.1-0.6 mm long.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 1.5-2 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus glabrous, or pubescent; base truncate; attached transversely.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 1.5-2 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus glabrous, or pubescent; base truncate; attached transversely.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate, or ovate; 1 length of spikelet; chartaceous; without keels; 5 -veined. Lower glume lateral veins obscure. Lower glume surface scabrous; rough above. Upper glume lanceolate; chartaceous; 1-keeled; keeled above; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma lanceolate; 1 mm long; hyaline; without keel; 1 -veined. Lemma apex entire, or dentate; 2 -fid; acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 4-5 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.
Morphology Reproductive morphology Flowers
Anthers 2; 0.3-0.5 mm long.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; linear; 1.2 mm long.
Distribution
Asia-temperate: China. Asia-tropical: India.
Reference
Andropogoneae. Jain 1993.
[GB]

Morphology General Habit
Annual. Culms geniculately ascending; slender; 15-35 cm long. Culm-internodes distally glabrous. Ligule a ciliolate membrane. Leaf-blades lanceolate.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Racemes 2-9; digitate; 0.5-2 cm long. Rhachis fragile at the nodes. Rhachis internodes filiform to linear. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels reduced to a stump.
Morphology Reproductive morphology Inflorescences Spikelets
Companion sterile spikelets represented by barren pedicels. Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 0.8-1.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; attached transversely.
Sterile
Companion sterile spikelets represented by barren pedicels.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 0.8-1.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; attached transversely.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; without keels. Lower glume surface convex; scabrous; rough on veins. Upper glume lanceolate; chartaceous; 1-keeled; keeled above. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma oblong; hyaline; without keel; 1 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 5-6 mm long overall; with twisted column. Palea absent or minute.
Morphology Reproductive morphology Flowers
Anthers 2; 0.2 mm long.
Distribution
Asia-temperate: Arabia.
Reference
Andropogoneae. Fl Arabia 2007.
[GB]

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

  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. 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

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. 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