MARIA GARCIASASHA ESPINOLA

CycadsCycas

Origins

Appeared in fossil record during the Triassic period, 225 million years ago.

Because cycads continue to survive they are called living fossils

Cycads are not related to ferns or palms

Seed bearing plants, classified as gymnosperms

The regions to which cycads are spread indicate their former distribution in Pangaea beforeit separated.

Belongs to the phylum Cycadophyta, native to warm regions.

Phylum Cycadophyta

Derived from two Greek words: kykas (palm) and phyto (plant)

Cycads are dioecious, as opposed to monoecious, and produce seeds on special leaves.

Dioecious: Have male and female cones on separate plants in the same species

History

One of the earliest seed plants

Were important food resource for dinosaurs

People became aware of cycads through two Arab naturalist who recorded that cycas was used for flour.

Geovanni Lerio on a trip to Brazil observed a species now classified as Zamia.

American Botanist C.J. Chamberlain studied cycads for about 15 years

Location

Parts of:

•Mexico

•Florida

•Central America

•Southeast Africa

•Australia

Structure

Types

There are nine different genera of cycads: Cycas revoluta, sago palm - dwarf palm like cycad of

Japan that yields years ago Zamia - any of various cycads of the genus Zamia;

among the smallest and most verdant cycads Ceratozamia - a small cycad of the genus Ceratozamia

having a short scaly woody trunk and fernlike foliage and woody cones; Mexico

Types

dioon - the genus Dioon; handsome palm like cycads with robust crowns of leaves and rugged trunks

Encephalartos caffer, kaffir bread - South African cycad; the fruit is sometimes used as food

macrozamia - treelike cycad of the genus Macrozamia: erect trunks and pinnate leaves and large cones with sometimes edible nuts; found in Australia

Reproduction

Gymnosperm: “naked seed” seeds that are exposedNot flowering plantsCones are the form of reproductionMale and female are distinguished in appearance Female: larger in diameterMale: elongated and narrowMale cones develop pollen. Carried by insects or

sometimes wind to the female cone. Seeds then develop inside female cones. If matured, the seeds will germinate and produce small seedling

There are more male cones rather than female cones

Uses

Can be grown in your gardenfood in some indigenous tribes (toxins in the

seeds must be removed so it can be safe to eat)

In Okinawa was considered a famine food, last resort during difficult times

 Regular consumption of starch derived from cycads are said to develop Lytico-Bodig disease (a neurological disease with symptoms similar to Parkinson's disease.)

Most threatened group of organisms

Cycads are the oldest living seed plants and have survived three mass extinction events!!

They are facing a growing threat of extinction so it would be ideal to plant and take care of cycads in gardens to help out the ecosystem.

Extinction and Conservation!