Zamia is a genus of cycad of the family Zamiaceae, native to North America from the United States (in Georgia and Florida) throughout the West Indies, Central America, and South America as far south as Bolivia. The genus is considered to be the most ecologically and morphologically diverse of the cycads, and is estimated to have originated about 68.3 million years ago.
Description
Zamia furfuracea leaves
The genus comprises deciduous shrubs with aerial or subterranean circular stems, often superficially resembling palms. They produce spirally arranged, pinnate leaves which are pubescent, at least when young, having branched and simple, transparent and coloured hairs. The articulated leaflets lack a midrib, and are broad with subparallel dichotomous venation. Lower leaflets are not reduced to spines, though the petioles often have prickles. The emerging leaves of many Zamia species are striking, some emerging with a reddish or bronze cast (Z. roezlii being an example). Z. picta is even more distinctive, being the only truly variegated cycad (having whitish/yellow speckles on the leaves).
Like all Zamiaceae, Zamia plants have "coralloid" (coral-shaped) roots which host nitrogen-fixing cyanobacteria. Stems are 3 to 25 centimetres (1.2 to 9.8 in) in diameter, and when arboreal, up to 5 metres (16 ft) tall. Leaves vary from 2 to up to 15 in number, and have an even number (5 to 60 pairs) of leaflets. petioles (leaf stalks) and rachis (leaf axis, to which leaflets are attached) may be smooth, or have prickles on the petiole and lower part of the rachis. Leaflets are linear to ovate and may be directly attached to the rachis, or may be on short petiolules. The edges of leaflets may be smooth, or may be toothed partly or around the whole leaflet. The morphology of leaflets is highly varied between even closely related species of Zamia, and within species and even within populations of a species. Studies have found that the amount of sun a plant is exposed to is...
