Cycadaceae

Cycas L.

First published in Sp. Pl.: 1188 (1753)
This genus is accepted
The native range of this genus is Kenya to Mozambique and W. Pacific.

Descriptions

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

Morphology General Habit
Palm-like dioecious evergreen plants with a single erect trunk (subterranean to 9 m tall) unbranched or branched
Morphology Trunk
Trunk rough, with persistent leaf bases, or eventually becoming smooth
Morphology Leaves
Leaves circinate at emergence, spirally inserted, unfolding to long fronds, in our area all simply pinnate (not divided)
Morphology Leaves Rachis
Rachis smooth or armed with short spines towards the base; leaflets (pinnae) numerous, alternate or subopposite, narrowly linear, coriaceous, with a single midvein and entire margins
Morphology Reproductive morphology Sporophylls
Female sporophylls spirally inserted, forming a compact dome in the centre of the crown, with 1-∞ laterally attached seeds ripening orange or red and a ±pinnate sterile terminal part Male sporophylls tightly and helically arranged in a large, elongated simple cone, wedge-shaped, tapering abruptly to a sharp, erect spine, with numerous pollen sacs on the abaxial surface.
Ecology
Cycads in New Guinea commonly occur in forest margins and on poor, sandy soils, sometimes seasonally inundated (Cycas apoa K.D.Hill) or on sand over calcareous substrate (C. rumphii Miq.) or in woodland savannahs and rough grassland from low altitude to 1600 m (C. schumanniana Lauterb.). Most species are capable of resprouting a foliage crown after fire and are therefore adapted to fire-prone habitats.
[TONG]

Gymnospermae, R. Melville. Flora of Tropical East Africa. 1958

Morphology General Habit
Shrubs or trees with simple, rarely branched, trunks clothed with woody leaf bases and bearing a crown of pinnate leaves
Morphology Leaves
Leaflets linear, entire, 1-nerved
sex Male
Scales of the male cones wedge-shaped, often long acuminate, closely imbricate, with ellipsoid pollen-sacs in groups of 3–5 on the lower surface
Morphology Reproductive morphology Cones
Female blades crowded round the stem apex, densely woolly at first, later spreading, elongated, widening upwards, with 1–5 pairs of erect ovules in marginal notches Scales of the male cones wedge-shaped, often long acuminate, closely imbricate, with ellipsoid pollen-sacs in groups of 3–5 on the lower surface
sex Female
Female blades crowded round the stem apex, densely woolly at first, later spreading, elongated, widening upwards, with 1–5 pairs of erect ovules in marginal notches
Morphology Reproductive morphology Seeds
Seeds ellipsoid or globose.
[FTEA]

Sources

  • Flora of Tropical East Africa

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

  • 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 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 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 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 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