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Palm-like plants with erect, cylindrical stems clad with persistent leaf bases (stems subterranean in some extra-Australian taxa). Leaves pinnate, spirally arranged, in seasonal growth flushes interspersed with cataphylls; lower pinnae often reduced to spines. Longitudinal ptyxis erect or rarely reflexed; horizontal ptyxis circinate. Pinnae with a single thick midrib and no lateral veins; stomata confined to abaxial surface in most species; individual ptyxis involute. Trichomes transparent, branched or simple. Male sporophylls aggregated into determinate cones and bearing numerous pollen sacs on abaxial surfaces; lamina with a simple sterile tip which is often produced into an upturned spine. Female sporophylls spirally arranged in an indeterminate, terminal rosette with the central axis continuing vegetative growth. Ovules 2-many, marginally inserted on the lamina and directed obliquely outwards ('ascending'); lamina apically dilated, pinnatifid, pectinate, toothed or entire. Seeds platyspermic, with a yellow, orange or brown, fleshy outer sarcotesta, and with or without spongy tissue beneath the inner sclerotesta.
Female strobilus either a loose apical whorl of fronds bearing erect ovules marginally (Cycas) or a terminal cone of thick and often woody scales bearing a pair of inverted ovules adaxially
Leaves usually long and pinnate, in close spirals, forming an often wide-spreading crown on the trunk and (except in one species of Macrozamia) intercalated with leathery scale-leaves
Trunk simple or sparsely branched, covered with spirally arranged leaf-bases and scale-leaves, either up to 15 m. tall or very short and almost subterranean
Males terminal or subterminal, composed of numerous leathery or fleshy flat or peltate scales bearing on the under-surface numerous pollen-sacs
Shrubs or small trees with thick, usually simple stems and a crown of pinnatisect leaves circinate in bud; leaflets often with spiny teeth
Staminate strobilus forming a terminal cone of leathery scales with numerous pollen-sacs on their abaxial surface
Female cones similar, the scales bearing a pair of inverted nude ovules on the lower side
Seeds large, drupe-like, with copious endosperm; cotyledons 2
Dioecious trees or shrubs
Cones dioecious
