^{(Photograph = Cleistocactus winteri, Peter Mansfeld)}

Introduction

Plants come in all shapes and sizes, from palm trees to carrots to grass. Most plants have leaves, and this affects their shape. They may have strong branches to hold up their leaves. What about plants that don’t have leaves?

The Details

Cacti have essentially no leaves. If they do have leaves, the leaves are tiny.  However, with no leaves they are free to have novel shapes. Cacti may form small balls, or columns, or barrels,  paddles, or may even grow thin stems to grow up through shrubs.

Often cactus stems are ribbed like accordions. The accordion shape permits cacti to shrink or enlarge as they lose or gain water. Because they lack leaves, cactus stems are exposed to intense sun–as a result their stems are often covered by a thick skin that prevents water loss.

Related Reading: The Cactus Explorer No. 11