Opuntia Genus

Cactus Family

Opuntias are the pricklly pear cacti. The plant is composed of flat pads. Glochids are present at the aeroles. Large spines are usually, but not always present. Classification at the species level is often rather difficult. The opuntias hybridize creating intergradations between species. For example, in the west foothills of the Sandia Mountains at 6,200 foot elevation Opuntia engelmanii, Opuntia polycantha, and Opuntia erinacea are common. Clear examples of each species abound. Examples of species with characteristics intermediate between erinacea and polycantha are also observed. Similiar descriptions are noted in many references.

Distinguishing between the different species of Opuntia can be difficult. To aid this process check the pages sorting opuntia (A-E), sorting Opuntia (E-R) and sorting opuntia (S-T). The most important single characteristic is location, then elevation. Next is the overall size of the plant. Remaining characteristics are those in the "sorting opuntia" pages. Note each characteristic before attempting an identification because many species hybridize. For more complete material see the "efloras" link below. Many of the characteristics herein are derived from efloras, Weber, or Harrington.

Generally the larger opuntias occur at the lower elevations in the warmer climes, for example in southern Arizona or around Big Bend, Texas. Smaller and medium sized opuntias tend to be widespread, for example fragilis and polycantha which occur througout the rocky mountain region. The genetic differences between the Opuntia are confusing to this author. They may eventually lead to a better classification of the opuntia. Presentlly the species are separated by the observed differences noted in the "sorting opuntia" links above.

efloras