Poaceae
Isachne

Isachne surgens Jansen

First published in Reinwardtia 2: 281 (1953)
This species is accepted
The native range of this species is Sulawesi (Mt. Bonthain). It is a perennial and grows primarily in the montane 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: threatened. Confidence: confident
[AERP]

Morphology General Habit
Perennial. Culms geniculately ascending, or decumbent; 80-100 cm long; 1 mm diam.; rooting from lower nodes. Culm-internodes smooth; distally glabrous. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths 15-80 cm long; mostly shorter than adjacent culm internode; glabrous on surface; outer margin hairy. Leaf-sheath oral hairs scanty. Ligule absent. Leaf-blades linear, or lanceolate; 6-7 cm long; 5-8 mm wide. Leaf-blade venation with 4-6 secondary veins. Leaf-blade surface scabrous; rough on both sides; glabrous, or puberulous; hairy abaxially. Leaf-blade margins unthickened, or cartilaginous; scaberulous.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; ovate; 4-5 cm long. Primary panicle branches spreading; 1 -nate; 1-2 cm long. Panicle branches capillary; flexuous; smooth. Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 1.7 mm long; breaking up at maturity; disarticulating below each fertile floret.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 1.7 mm long; breaking up at maturity; disarticulating below each fertile floret.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes deciduous; similar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 1.7 mm long; 1.1 length of upper glume; 1 length of spikelet; membranous; without keels; 7 -veined. Lower glume lateral veins obscure. Lower glume surface glabrous. Lower glume apex obtuse. Upper glume oblong; 1.5 mm long; 0.9 length of spikelet; membranous; without keels; 7 -veined. Upper glume primary vein obscure. Upper glume surface glabrous. Upper glume apex obtuse.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets male; with palea; separately deciduous. Lemma of lower sterile floret oblong; 1.7 mm long; 1.4 length of fertile lemma; 1 length of spikelet; chartaceous; 5 -veined; obscurely veined; glabrous; obtuse. Fertile florets bisexual, or female. Fertile lemma oblong; 1.2 mm long; coriaceous; without keel. Lemma surface puberulous. Lemma margins involute. Lemma apex obtuse. Palea coriaceous; 2 -veined.
Morphology Reproductive morphology Flowers
Anthers 3.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp.
Distribution
Asia-tropical: Malesia.
Reference
Isachneae. Jansen 2001.
[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

  • 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