Plants superficially palmlike or fernlike, perennial, evergreen, dioecious. Stems subterranean with exposed apex or aboveground, fleshy, stout, cylindric, simple or irregularly branched. Roots with small secondary-roots; corallike roots developing at base of stem at or below soil surface. Leaves pinnately compound, spirally clustered at stem apex, leathery, petiole and rachis unarmed [with stout spines]; leaflets entire or dentate [spinose], venation dichotomous [netted]; resin canals absent. Cones axillary, appearing terminal, short-peduncled [sessile], disintegrating at maturity; sporophylls densely crowded, spirally arranged, often covered with indument. Pollen cones soon shed, generally smaller and more numerous than seed-cones; sporophylls bearing many crowded, small microsporangia (pollen-sacs) adaxially; pollen spheric, not winged. Seed-cones persistent for a year or more, 1 (–2) per plant, nearly globose to ovoid, tapering sharply or blunt at apex; sporophylls peltate, thickened and laterally expanded distally, bearing 2 (–3) ovules. Seeds angular, inner coat hardened, outer coat fleshy, often brightly colored; cotyledons 2.

Distribution

Primarily tropical to warm temperate regions, North Americ, Central America, South America, Africa, Australia.

Discussion

Genera 9, species ca. 100 (1 genus, 1 species in the flora).

Selected References

Candolle, A. L. P. de. 1868. Cycadaceae. In: A. P. de Candolle and A. L. P. de Candolle, eds. 1823--1873. Prodromus Systematis Naturalis Regni Vegetabilis.... Paris etc. Vol. 16, part 2, pp. 522--547.

Johnson, L. A. S. 1959. The families of cycads and the Zamiaceae of Australia. Proc. Linn. Soc. New South Wales 84: 64--117.

Schuster, J. 1932. Cycadaceae. In: H. G. A. Engler, ed. 1900--1953. Das Pflanzenreich.... Berlin. Vol. 99[IV,1], pp. l--168.

Lower Taxa

Zamia

Illustrations

	Family ⠉	Taxon	Illustrator ⠉
	Zamiaceae Ginkgoaceae	Zamia integrifolia Ginkgo biloba	John Myers John Myers