The plant body of cycas is a sprophyte. It is differentiated into root, stem and leaves.
Stem:
It has an unbranched, stout, erect, columnar stem. The stem is covered by armor of thick persistent rhomboidal leaf bases.
Leaves:
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Leaves are of two types; brown scale leaves and large green foliage leaves arranged in whorls at the top of the stem. The young foliage leaves and scale leaves are covered with hairs called ramenta. Foliage leaves are petiolate, unipinnately compound and paripinnate.
Leaf base is broad. Petiole continues into rachis. Rachis has two lateral grooves from which arise 50-200 pairs of sessile, linear, lanceolate, tough and leathery pinnae or leaf-lets. Each leaflet is entire, having only a single mid vein. It shows circinate venation when young.
Root:
The roots are of two types – normal tap roots and coralloid roots. The tap roots are short lived. Soon they are replaced by a number of adventitious roots. The adventitious roots fix the plant in the soil and absorb water and minerals from the soil. Some of the adventitious roots grow laterally and come out of the soil surface.
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These roots are known as coralloid roots as they appear like corals. Coralloid roots are negatively geotropic, dichotomously branched and greenish brown in color. These roots get infected by cyan bacteria (blue green algae) such as Anabaena, Nostoc, and Oscillatory which form a ring in the cortex known as algal zone. The algal zone fixes atmospheric nitrogen in the coralloid roots.