Zamia L.

First published in: Sp. Pl., ed. 2. 2: 1659 (1763)

Etymology: From the Greek azaniae a pine cone

Synonyms:

• Aulacophyllum Regel
• Chigua D.W.Stev.
• Palmifolium Kuntze

Description: Habit: dioecious palm- or fern-like shrubs with aerial or subterranean, pachycaul, cylindrical or globose stems, with few to many leaves. Leaf bases mostly not persistent. New leaves emerging singly or in flushes. Dichotomous branching common in geophytic species, basal offsets ("suckers") produced by some species. Leaves: pinnate, spirally arranged, interspersed with cataphylls, lower leaflets not reduced to spines. Petioles often with prickles. Longitudinal ptyxis erect, horizontal ptyxis erect. Leaflets simple, with spiny margins in some species, with numerous bifurcating parallel veins and no distinct midrib, leaflets articulated, inserted near the edges of the rhachis towards the adaxial side, lacking a 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 and simple, transparent and coloured hairs. Microsporophylls: spirally orthostichous, aggregated into stalked or sessile male cones and each with a simple sterile apex, which is often flattened or faceted, sometimes weakly bilobed, never produced into an upturned spine. Each microsporophyll bearing numerous microsporangia (pollensacs) on the abaxial surfaces. Microsporangia opening by slits. Pollen cymbiform, monosulcate. Megasporophylls: spirally orthostichous, aggregated into stalked or sessile female cones. Sporophylls simple, appearing peltate with a simple dilated apex which is usually hexagonal, often flattened or faceted, sometimes weakly bilobed, never produced into an upturned spine. Ovules two (rarely three), sessile, orthotropous, inserted on the inner (axis-facing) surface of the thickened lamina and directed inwards ("inverted"). Seeds: subglobular to oblong or ellipsoidal, with a red, orange, yellow or rarely white 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.