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Cycads (a writeup by Paloma Garden with links and some edits added by J Brew) More Cycad info at The Cycad Pages by Ken Hill

Cycads are among an exclusive group of plants which can claim to be truly ancient, a reminder of how the earth once looked. During the Jurassic and early Cretaceous periods (around 200 million years ago), they would have dominated the vegetation of the day, providing nourishment to grazing dinosaurs, perhaps. Botanically they are grouped with gymnosperms, the cone-bearing plants alongside the conifers. But in fact they are quite unique and should not be confused with palms or ferns. The 292 known species found in 11 genera are amongst the most ancient of all plants surviving today.

The cycad you see before you is Macrozamia moorei, from Queensland, Australia. Their natural habitats are spread across Australasia, Asia, Africa, and South America, roughly within the boundaries of the tropics of Cancer and Capricorn. The main genera included under the umbrella of the cycads are: [info added by J Brew)

The Cycadaceae Family (1 genus) Cycas (90 species),

The Zamiaceae family (8 genera) containing the Encephalartoideae subfamily
Dioon (11 species),
Macrozamia (38 species),
Encephalartos (62 species),
Lepidozamia (2 species),
and the subfamily of Zamioideae containing
Zamia (more than 50 species),
Microcycas (1 species),
Ceratozamia (16 species), and
Chigua (2 species)

The Stangeriaceae family (2 genera) contains Stangeria (1 species) and Bowenia (2 species)

Back in the Mesozoic era they thrived in the warm, moist, permanently shaded conditions of that time. They would have been growing alongside plants such as Araucaria, Pandanus, Equisetum (horsetails) and other wet-seeded, shade-dependent plants. They are now to be found in ever-shrinking habitats with mesic to semi-arid conditions. Cycads are endangered in the wild, some on the edge of extinction. The reason for this is a combination of irresponsible agriculture and wolfish collectors. All cycads are now protected by CITES (Convention on International Trade in Endangered Species on Wild Flora and Fauna). These amazing plants have survived ice ages, droughts, floods, and bush fires, let’s hope they can survive the threat posed by mankind. There are cycads to suit a wide range of climates, find out which is most suited to your particular environment. They require good drainage, good soil, warmth, and plenty of water. Most require full sun, apart from rainforest species which would be more suited to dappled shade. Some are frost hardy, but in general it will impede their growth or vigour. A rule we have found here is that the plants that have bluish foliage are hardier than the green varieties. Cycads are susceptible to herbicide damage, but we have found that Linuron is effective with no detrimental effects. Propagate from seed, which can be slow, or by the removal of suckers or trunk offsets. Enjoy walking through our cycads but remember to listen out for the beat of a pterodactyl’s wings!!!

Also see Paloma Gardens, Clive & Nicki Higgie, Fordell, Wanganui, North Island, New Zealand Northwest Horticulture Society November, 2005 tour