Page "Cactus" Paragraph 9

Remaining cacti fall into only two genera, Pereskia and Maihuenia, and are rather different, which means that any description of cacti as a whole must frequently make exceptions for them.

Pereskia species superficially resemble other tropical forest trees.

When mature they have woody stems that may be covered with bark and long-lasting leaves that provide the main means of photosynthesis.

Their flowers may have superior ovaries ( i. e., above points of attachment of the sepals and petals ), and areoles that produce further leaves.

The two species of Maihuenia have small globe-shaped bodies with prominent leaves at the top.