Low spreading shrubs to compact conical trees to 15 m high. Leaves arranged alternately in whorls of 3, completely enclosing terete ultimate branches, lower oblong portion adnate to the stem, upper triangular part free and overlapping the base of adjacent leaves, outer surface rounded or keeled. Male cones terminal or lateral on ultimate branches, ovoid to cylindric, sporophylls in alternate whorls of 3, 3–6 whorls per cone, 2 or 3 sporangia per sporophyll. Female cones globular, with 6 valves in 2 alternate whorls of 3, whorls differing in size and shape; small dorsal appendage at apex of valve conspicuous or inconspicuous; columella small, sometimes lobed. Seeds borne on columella and valves, 30 or more per cone, 1–3 winged.
19 species; 17 endemic to Australia (2 to New Caledonia), 6 species in Victoria.