The very idea of having Mesozoic age plants in a garden...

The genus Zamia is native to tropical America. Fossil specimens of this genus have been found in such diverse places as Tennessee, Puerto Rico, and Greenland. Most of the fossils date to the age shortly after the extinction of the dinosaurs. These are plants belonging to the Order Cycadales, some of the first plants to produce seeds. Palm-like in appearance, cycads are much older than palms. This order of plants somehow survived the Cretaceous-Tertiary event where after dinosaurs no longer walked the Earth. These plants have been tough in the face of adversity, but the habitat destruction these relicts face today may bring an end to a truly remarkable order of plants.

Zamias and other cycads possess a number of characteristics making them unique to the plant world. Zamias are dioecious, either male or female. The reproductive structures are cone-like; the male cone when shedding pollen and female cone when receptive to pollination produce heat. The temperatures of the cones may exceed the ambient temperature by as much as 17 degrees Centigrade. This increase in temperature is believed to attract insects that act as pollinators.

The sperm cells are flagellated. When released from the pollen grain, these cells "swim" to the ovule. The ginkgo is the only other seed plant with motile sperm.

Zamias produce coralloid roots. These roots appear in clusters at or near the surface of the soil. Coralloid roots contain symbiotic cyanobacteria (blue-green algae) which fix nitrogen from the atmosphere. In poor, rocky, and sandy soils, the cyanobacteria may be the main source of nitrogen necessary for the growth of the cycad. And in dry soils, the coralloid roots may be the only place where the cyanobacteria can survive.

Zamias have contractile stems. The main stem of a Zamia is subterranean, usually only the top of the stem or the leaves can be seen. Specialized cells in the cortex and pith of the stem are able to collapse. The collapse of these cells causes the stem to be pulled deeper into the soil. This adaptation protects the stem from loss of water during drought and heat damage during fires.

Zamias contain macrozamin, an extremely toxic poison. Sheep and cattle that have grazed on Zamias decline in health due to a neurological disorder called the zamia staggers. This disorder in animals is very similar to amyotrophic lateral sclerosis (Lou Gehrig's disease) in humans. Consequently, many medical studies have been conducted with this toxin in an attempt to discover the cause of ALS.

A high quality starch is produced and stored within the stem. Numerous Native Americans discovered how to remove macrozamin and retain the starchy flour for bread. And here is where an unusual coincidence occurred. It is thought that Linnaeus named the genus Zamia from the Greek word azaniae, which means pine cones or from the word zemia, which means hurt, damage, or loss. In 1492 when the Spanish landed on the island of Hispaniola, they found the Taino. One of the main sources of food for the Taino was the starchy flour from a species of Zamia. The Taino worshipped a pantheon of nature spirits called zemis (pronounced zah mees). One of these nature spirits was, of course, the Zamia which supplied the flour for their bread.

For more information about Zamia and other cycads, click on the link:

http://www.plantapalm.com/vce/toc.htm