Acanthospermum Schrank

First published in Pl. Rar. Hort. Monac.: t. 53 (1820)
This genus is accepted
The native range of this genus is Tropical America.

Descriptions

M. Thulin et al. Flora of Somalia Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Annual herbs, dichotomously branched
Morphology Leaves
Leaves simple and opposite
Morphology Reproductive morphology Inflorescences
Capitula in cymes, radiate
Morphology Reproductive morphology Inflorescences Bracts Phyllaries
Phyllaries in two rows, the inner row forming an involucre with straight or hooked spines
Morphology Reproductive morphology Flowers Florets
Ray florets 5–8, small, female, each enclosed in a phyllary or bract that hardens in fruit; disk florets functionally male, surrounded by soft bracts/paleae
Morphology Reproductive morphology Fruits
Achenes enclosed by the hardened involucre; pappus absent.
Distribution
Seven species in Central and South America, one pantropical weed.
[FSOM]

Compositae, H.J. Beentje. Flora of Tropical East Africa. 2002

Morphology General Habit
Annual or perennial herbs
Morphology Leaves
Leaves opposite
Morphology Reproductive morphology Inflorescences Capitulum
Capitula solitary, axillary or in branch forks, sessile or shortly stalked, heterogamous, radiate, enlarging in fruit; involucre of two series, the outer herbaceous, the inner closely enveloping the outer florets; receptacle paleate
Morphology Reproductive morphology Flowers Florets
Inner florets bisexual but functionally male, campanulate or infundibuliform; style branches connate, club-shaped; anthers with truncate bases and ovate apical appendix Outer florets female, radiate with small ray; style branches strongly divergent, linear and obtuse
Morphology Reproductive morphology Fruits
Achenes of the female florets covered by the indurate and echinate phyllaries, the achene itself smooth; achenes in disc florets abortive; pappus absent.
[FTEA]

Sources

  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Kew Backbone Distributions

    • 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
  • 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