Cycads are a group of gymnosperm trees and 1) …………………….. They are woody, seed producing plants with no flowers or fruit. Cycads often look similar to palm trees with branchless stems and a crown of leaves at the top of the tree, but they are not 2)………………closely related to palm trees.
The cycads are widely distributed around the world but are mostly found in tropical areas. Many species are threatened with 3) ……………………….. due to habitat loss.
Cycad typically have short 4)……………………… topped off with a green crown of large leaves. Fallen leaves of the past leave leaf 5) ………………………that encircle the stem.
Most species do not grow more than a few meter tall. Hope’s cycad of Australia is one of the tallest species and is known to reach 20 m in height. More primitive cycads were often much taller than the majority of cycad species that currently exist.
The roots of cycads look very unusual and are known as coralloid roots because they have a similar shape to coral. Their roots share an important 6)………………………. with the blue-green algae, cyanobacteria. The roots provide the cyanobacteria with protection while the cyanobacteria supplies the roots with nitrogen based nutrients.
The distribution of cycads is mostly limited to tropical regions. They are found naturally in every continent except Europe and Antarctica and are now also commonly planted garden plants.
There is7) ………………………..around 250 species of cycads living on Earth. Cycads are an extremely old group of plants. They are known to have been present at least 280 million years ago from the dating of fossils found in China. They were most 8)…………………….in the Jurassic Period between 201-145 million years ago, occasionally referred to as the ‘Age of Cycads’ by botanists. At that time they they made up around 20% of the world’s plant 9)…………………………
Cycads produce separate male and female plants with distinct cones. Cones are often brightly colored in reds, oranges and yellows. Pollination is believed to be mostly completed by weevils and small bees which are attracted to seeds by heat and scent. They reproduce with seeds which have fleshy outer 10)………………. to attract animals. Animals are the main vector for dispersing seeds into new areas.
Your choice: (you need only 10 words!)
relationship, pesky, extinction, layers, thorns, currently, trunks, at all, species, scars, shrubs, abundant