…or is it not a cactus?  Cacti and other succulents are gaining popularity both as landscape ornamentals and as potted plants.  There is some confusion as to the difference between cacti and succulents.  Cacti (singular cactus) is the commonly used name for a group of plants in the flowering plant family CACTACEAE.  Succulents is a commonly used term for many plants across more than 60 plant families including CACTACEAE. Therefore, all cacti are succulents but not all succulents are cacti.

Succulents can be found in many different regions around the world. By contrast, most species of CACTACEAE are native only to the New World which refers to North, Central and South America.  Mexico has the greatest number and variety of species.

Cacti can be distinguished from other succulents by the presence of areoles: small, cushion-like structures with trichomes (hair-like) and in almost all species, spines (highly modified leaves) and on a few species, glochids (barbed bristles found on Chollas and Prickly pears – Ouch!).  In most cacti species, leaves are absent, greatly reduced or highly modified.  Stems instead of leaves are the primary sites for photosynthesis and water storage.  These stems also establish the overall shape of the mature plant.

Non-cacti succulents typically have leaves that may be   swollen and “juicy” or thick and leathery looking.  The leaves and stems may have spines or thorns (modified stems) or prickles (corky projections arising from dermal tissue).  The mature structure of most non-cacti succulents is determined by the shape and arrangement of their leaves as opposed to their stems as is found with cacti. Non-cacti succulents do not have areoles. 

Why grow succulents? 

· Most are easy to grow and are able to thrive with a minimum of care.

· Most are attractive and may have a striking and unusual appearance.

· Many come in a variety of colors.

· Some have medicinal uses.

· Most require modest amounts of water and fertilizer.

· Most need lots of light but a few species will tolerate partial shade or lower light conditions.

· Pests are a rare concern.