The colors below indicate the kind of documentation available for this species
in the California counties where it occurs.
Wolf's Cholla Opuntia wolfii (Cactaceae)
Green plants need carbon dioxide from the atmosphere to carry out photosynthesis. They have to open their stomata (minute openings in the epidermis of leaves and stems) to let the gas in. Water evaporates from the stomata at the same time. If the water is not replaced by the roots, which can occur in the dry desert climate, plants can dry out and eventually die. To circumvent this problem, some cacti are largely dependent upon nighttime accumulation of carbon for photosynthesis because their stomata are closed during the day to retard water loss. This is advantageous under the conditions of high light intensity and water stress under which many succulent plants live.
DISTRIBUTION: Dry places above valley floors above the western edge of the Sonoran Desert; 300-1200 m.
