First published in: Enum. Pl. Austral. Occ.: 3. (1930)

Etymology: From the Greek makros, large, and Zamia a genus of cycads

Description: Habit: dioecious palmlike shrubs with aerial or subterranean, pachycaul, cylindrical stems, with few to many leaves and persistent leaf bases. Leaves: pinnate, spirally arranged, interspersed with cataphylls, lower leaflets often reduced to spines. Longitudinal ptyxis erect, horizontal ptyxis erect. Leaflets simple or dichotomously divided, with numerous parallel veins and no distinct midrib, leaflets inserted near the edges of the rhachis towards the adaxial side, often with a paler or differently coloured basal gland; stomata on lower surface only or on both surfaces; epidermal cells elongated parallel to long axes of leaflets. Leaves pubescent, at least when young, with branched or simple transparent hairs. Microsporophylls: spirally aggregated into determinate, stalked male cones and each with a simple sterile apex, which is often produced into an upturned spine. Each microsporophyll bearing numerous microsporangia (pollensacs) on its abaxial surfaces. Microsporangia opening by slits. Pollen cymbiform, monosulcate. Megasporophylls: spirally aggregated into determinate, stalked female cones. sporophylls simple, appearing peltate with a simple dilated apex or lamina which is often produced into an upturned spine. Ovules two (rarely three), sessile, orthotropous, inserted on the inner (axisfacing) surface of the thickened lamina and directed inwards ("inverted"). Seeds: subglobular to oblong or ellipsoidal, with a red or less commonly yellow, orange or brown fleshy outer sarcotesta. Endosperm haploid, derived from the female gametophyte. Embryo straight; with 2 cotyledons that are usually united at the tips and a very long, spirally twisted suspensor. Seeds radiospermic; germination cryptocotular.