Poaceae
Arthraxon

Arthraxon jubatus Hack.

First published in A.L.P.P.de Candolle & A.C.P.de Candolle, Monogr. Phan. 6: 358 (1889)
This species is accepted
The native range of this species is SW. India. It is an annual and grows primarily in the seasonally dry tropical biome.

Descriptions

Morphology General Habit
Annual. Culms rambling; slender; 10-22 cm long. Culm-nodes pubescent. Leaf-sheaths pilose; with simple hairs, or tubercle-based hairs. Ligule a ciliolate membrane; 0.4-0.7 mm long. Leaf-blade base broadly rounded. Leaf-blades lanceolate; 1.4-3.9 cm long; 3-6 mm wide. Leaf-blade surface pubescent; hairy on both sides. Leaf-blade margins ciliate.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Racemes 2-3; paired, or digitate; 2 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform; 4-5.1 mm long. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 1.7-2.6 mm long; ciliate.
Sterile
Companion sterile spikelets well-developed; male; lanceolate; 3.9-5 mm long; shorter than fertile. Companion sterile spikelet glumes 4-7 -veined. Companion sterile spikelet lemmas 2; enclosed by glumes.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 6-8.4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base truncate; attached transversely. Spikelet callus hairs 1-1.5 mm long. Companion sterile spikelets well-developed; male; lanceolate; 3.9-5 mm long; shorter than fertile. Companion sterile spikelet glumes 4-7 -veined. Companion sterile spikelet lemmas 2; enclosed by glumes.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 6-8.4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base truncate; attached transversely. Spikelet callus hairs 1-1.5 mm long.
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; 2-4 -veined. Lower glume surface asperulous; rough on veins. Upper glume lanceolate; chartaceous; 1-keeled; keeled above; 3 -veined. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1.6-2.2 mm long; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma lanceolate; 2.2-3.9 mm long; hyaline; without keel; 1 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 75-150 mm long overall; with twisted column. Column of lemma awn 18-46 mm long; glabrous. Palea absent or minute.
Morphology Reproductive morphology Flowers
Anthers 3; 0.7-1.3 mm long.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp.
Distribution
Asia-tropical: India.
Reference
Andropogoneae. Welzen 1993.
[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: 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

  • 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

  • Kew Science Photographs

    • Copyright applied to individual images