Centennial Museum gecko logo

Desert Diary
Plants/Cactus Leaves


Cacti are some of the most bizarre plants imaginable. Whether the flat pads of prickly pear, the cylindrical stems of cholla, or the tall, branched columns of saguaros and the like, "different" is the word. Nevertheless, these are plants akin to other plants, just marching to the beat of a different drummer.

Of course, some similarities are obvious, such as having chloroplasts with chlorophyll to process carbon dioxide and water into food molecules by using the energy of light. Flowers, beautiful in almost all species, forge another connection with the mainstream that everyone can recognize. But perhaps the most telling of characteristics is seen only in the initial stages of growth, as the cactus plant bursts forth from seed. For what is it that emerges? A pad of the prickly pear? A cylinder of cholla? No, a pair of ordinary-appearing leaves, such as might be seen in any of a number of plants. Just as the embryos of animals often reveal their deep relationships with other kinds, so do our cacti give away the secrets of their ancestry.
pen and ink


Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.

Young cactus showing the first leaves

A baby cactus with its first leaves showing. Photograph by A.H. Harris.