Updated: Mar 18, 2019
Cycads are group of unique plants that appeared on the planet during Permian, 280 million years ago. These plants were dominant during Jurassic and Triassic periods.
Number of cycads started to decline when flowering plants appeared on the Earth. Scientists have described 305 species of cycads so far, but they believe that true number of cycads is much bigger (more than 400 species in total).
Cycads can be found around the world. 70% of all species are native to China, Vietnam, Australia, South Africa and Mexico. Cycads can survive in different habitats: tropical rainforests, deserts, swamps, sand and rocky areas.
25% of all species of cycads are critically endangered and 15% are listed as vulnerable due to habitat loss and uncontrolled collecting of plants from the wild.
•Size of cycads depends on the species. They can reach few inches or several feet in the height.
• Cycads have cylindrical woody stem without branches. Stem is covered with corky bark.
•Crown consists of large, hard and elongated leaves that grow straight from the stem. Leaves are arranged in the form of rosette. New leaves appear in the center of the crown.
•Cycads have either pinnate (feathery) or deeply cut evergreen leaves.
•Certain types of cycads shed their leaves during extremely hot and dry season.
•Some species of cycads look like palm trees, while others look like ferns at the first glance.
•Despite similarities in morphology, cycads, palms and ferns are not genetically related.
•Cycads live in symbiosis (mutual beneficial relationship) with cyanobacteria which are able to fixate atmospheric nitrogen. These bacteria produce neurotoxin that can be found in various parts of the plant, including the seeds.
• Cycads do not produce flowers. Male and female reproductive organs develop on separate plants (dioecious). Male plants produce egg-shaped cones that are usually yellow to brown in color. Female plants develop ovules and seeds on leafy structures called sporophylls.
•Wind and beetles are in charge for the pollination. Cycads produce specific smell which attracts beetles and ensures successful pollination.
•Cycads produce small seeds that are covered with yellow or reddish flesh. Even though seeds contain toxin, they are used in human diet in some parts of the world.
•Cycads can be cultivated as houseplants. They can be propagated via seed or tissue cuttings.
•Cycads are source of food for many animals. Larvae of certain butterflies and ants eat secretion from the leaves, cattle feeds on the leaves, while fruit bats eat seeds.
•Cycads were used for the production of flour in the 9th century in India.
•Certain types of cycads are known as bread trees because they contain starch which is important part of diet of indigenous people.
•Leaves and cones of cycads are used in traditional Asian medicine.
•Most cycads grow slowly, but they can survive over 1000 years in the wild.
HOW TO CARE FOR A CYCAD
1. Place the cycad in a sunny location, but avoid hot afternoon sunlight, especially from behind glass. A window that receives direct morning sunlight is ideal if growing inside. If growing outside, place the cycad where it will receive direct morning sun only or partially shaded afternoon sunlight.
3. Water cycads whenever the surface of the soil feels dry to the touch during the spring and summer. Water the cycad until soaked but allow the water to drain completely. Water once a month or so during the winter months and only when the soil is dry to the touch.4. Fertilize cycads once in early spring and again in early-to-mid summer. Fertilize cycads using 19-6-12 granular slow-release fertilizer. Sprinkle 3 tablespoons of the granular fertilizer for every 2-foot-square area and mix it into the top 2 inches of soil. Water well after applying fertilizer.
5. Prune off lower fronds of the cycad as they yellow and die. Cut the fronds back to around 1 to 2 inches from the trunk. Discard the fronds and take away any dead fronds from the area around the base of the cycad. Decaying fronds can spread disease to the plant if not removed.