Casuarina L.

First published in Amoen. Acad. 4: 143 (1759)
This genus is accepted
The native range of this genus is Tropical Asia to W. Pacific.

Descriptions

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

Morphology Branches
Branchlets with deep and narrow grooves
Morphology Reproductive morphology Fruits Infructescences
Infructescences with ± thin and inconspicuous bracts
Morphology Reproductive morphology Fruits
Fruits grey or yellowish-brown, dull.
Distribution
14-17 species native to Australia, south-east Asia and the islands of the Pacific
Note
See Friis (1980) for a discussion of the authority and date of publication of Casuarina and C. equisetifolia.
[FSOM]

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution
A genus of about 17 species, mostly Australian, including the widespread littoral species Casuarina equesitifolia L., which occurs in southern India, throughout Malesia, Australia and the Pacific. Five species in New Guinea, one in the Solomon Islands.
Morphology General Habit
Trees to 30 m tall, photosynthetic twigs rounded in cross-section, mostly unbranched, deeply grooved, concealing stomata
Morphology Leaves
Leaves scale-like, in whorls of 5–18, acute at apex
Morphology Reproductive morphology Inflorescences
Inflorescences of male flowers terminal, erect, simple spikes; that of female flowers axillary, on persistent branchlets
Morphology Reproductive morphology Flowers
Flowers unisexual and plants dioecious or monoecious; male flowers with 1–2 caducous tepals, stamen 1; in female flowers ovary initially with 2 carpels, 1 carpel aborting, 1 ovule per carpel, style 1, stigmatic branches 2
Morphology Reproductive morphology Fruits Infructescences
Infructescence globose to ovoid, bracts woody, about as broad as long, bracteoles barely protruding from surface, inserted perpendicularly to infructescence axis
Morphology Reproductive morphology Fruits
Fruit a samaroid nut.
Ecology
In New Guinea, Casuarina occupies a range of habitats, from sandy coasts, littoral and swampy habitats close to sea level to highland forests up to about 2000 m.
Recognition
The genus can be recognised by the photosynthetic twigs that are mostly unbranched and deeply grooved, and 5–18 acutely pointed leaves per whorl. The infrucescences are on short axillary ‘peduncles’ on the persistent branches below the deciduous twigs, with the bracts and bracteoles not protruding far above the surface.
[TONG]

Casuarinaceae, C.M. Wilmot-Dear. Flora of Tropical East Africa. 1985

Morphology General Habit
Trees or shrubs
Morphology Stem
Deciduous stems with narrow grooves
Morphology Reproductive morphology Fruits
Fruit bracteoles thick or thin, with or without dorsal protuberance; bracts relatively inconspicuous, not elaborately thickened Samaras dark brown or black and shiny, or pale grey or fawn with surface pattern of minute slightly raised wavy lines.
[FTEA]

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit
Trees of pine-like aspect, with green, jointed, angular, striate branchlets that perform the function of leaves; leaves reduced to minute scales, these borne in whorls at the nodes and often short-connate into a sheath
Morphology Reproductive morphology Flowers
Flowers unisexual, the plants monoecious; staminate flowers borne in narrow cylindric spikes on the ends of short lateral branchlets, several bracts combining at each node of the spike to form a serrate cup over the edge of which hang several stamens; each stamen represents a male flower with a concealed 1- or 2-segmented perianth and 2 bracteoles. Pistillate flowers in lateral, dense spherical heads, each female flower in the axil of a bract, without a perianth but subtended by 2 bracteoles; ovary small, 1-celled, with 2 long-exserted stigmas; ovules 1 or 2
Note
After fertilization the pistillate flower-head becomes hard and cone-like, the woody bracts and bracteoles subtending winged achenes
Morphology Reproductive morphology Seeds
Seed solitary, without endosperm.
[Cayman]

Uses

Use
Several widely cultivated and relatively fast growing trees.
[FSOM]

Use
It is commonly cultivated for timber, nitrogen fixation and as a shade tree, particularly for coffee plantations.
[TONG]

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
  • Flora of the Cayman Islands

    • Flora of the Cayman Islands
    • 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.
  • Interactive Key to Seed Plants of Malesia and Indo-China

    • The Malesian Key Group (2010) Interactive Key to Seed Plants of Malesia and Indo-China (Version 2.0, 28 Jul 2010) The Nationaal Herbarium Nederland Leiden and The Royal Botanic Gardens Kew
  • 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
  • Trees of New Guinea

    • Trees of New Guinea
    • http://creativecommons.org/licenses/by-nc-sa/3.0