PHILIPPE PSAILA / SCIENCE PHOTO LIBRARY PHILIPPE PSAILA / SCIENCE PHOTO LIBRARY
Cacti. These are golden barrel cacti (Echinocactus grusonii). A large specimen is at upper left. The smaller, extremely spiny specimens demonstrate why this cactus is sometimes called the step-mother's cushion. Cacti are plants that have evolved in arid environments. They have tissues adapted to minimise water loss. Cactus leaves are reduced to narrow spines, and the plant surface is covered in a thick, waxy outer layer. Many cacti also have a means of storing water.
Model release not required. Property release not required.