Cycads

They appeared at the end of the Permian period (about 230 millions of years ago) and had a great expansion throughout the world during the Jurassic period, 150 to 200 millions (of )years ago while dinosaurs and reptiles were reigning upon the animal world. The actual Cycadales have kept their archaic characters that make of them primitive vascular plants, "living fossils".

The Cycads are trees with a rarely ramified aerial trunk keeping all its foliar scars or with an underground tuberous axis surmounted by a crown of leaves forming a spiral. Although they look like palms, the Cycads are plants with naked seeds (Gymnosperms) such as conifers. The Cycads have male or female heads, they are dioecious plants.

Some species produce a sago of lower quality than sago-trees (palms), but in an large enough quantity so these plants are overexploited in their natural environments. In Japan, where Cycas revoluta is actively propagated in nurseries, the sago is exploited and used as a mixture people spread on bread. Some species’ fruits have medicinal properties if they are used in small quantities but eating some parts of these plants such as the seeds can be the origin of serious poisonings.

Cycads have been regressing – if it is not disappearing – for a long time, they are now gathered in 4 families shared out 11 genera and 275 species benefiting of the Washington Convention about plants protection. There is an important endemism in the hot areas of the globe, from shade forests to semi desert stations.

Here is how the genera are shared out:

Boweniaceae family :
Bowenia (2 species) : Australia

Cycadaceae family :
Cycas (90 species) : West coast of Africa, Madagascar, India, South East Asia, Japan, Malaysia, Oceania

Stangeriaceae family :
Stangeria (1 species) : South Africa

Zamiaceae family :
Ceratozamia (16 species) : Mexico, Guatemala, Belize
Chigua (2 species) : Colombia
Dioon (11 species) : Mexico, Honduras, Nicaragua
Encephalartos (62 species) : Africa
Lepidozamia (2 species) : Australia
Macrozamia (38 species) : Australia
Microcycas (1 species) : Cuba
Zamia (50 species) : tropical America

Our collection presents circa 60 species gathered in 8 genera