DESCRIPTION: Shrub to 20'. Branches are long (rarely branched), and radiate upward from a short trunk at ground level. Spines are long and present along branches. Leaves are simple, smooth-edged, oval, and green. Primary leaves have a petiole that turns into a spine when the leaf blade falls off. Secondary leaves (without petioles) then form at the base of the spine. Flowers bloom Feb. - May, depending on elevation and other factors. Flowers are red, tubular, about 1" long each, and grow in clusters at the ends of the branches. Fouquieriaceae (Ocotillo) Family, as is the Boojum (F. columnaris).
NATURAL HISTORY: Despite having no leaves much of the year and having spines, an ocotillo is NOT a cactus. Cactus spines grow out of areoles and the flowers are very different (see Cactaceae Family). However, they are similar in more ways than just having spines and often being leafless. They have very shallow roots like most cactuses. They can photosynthesize in their stems, without leaves, like cactuses. Finally, they act as if they are CAM-idling (which cactuses do), even though they are C3 plants, by so quickly producing full-grown leaves following rain.

Ocotillo nectar is sought out by hummingbirds (as expected judging by their red color and tubular shape), but also by Carpenter Bees and Verdins who don't have the ability to go into the flower the "right way." Instead, they "cheat" by cutting a hole at the base of the tubular flower and getting at the nectar that way. This is called "cheating" because they are bypassing the pollen-bearing anthers, thus potentially not contributing to the pollination (and future) of the plant. However, pollen may still be transferred just through the walking around on the flowers. By the way, the flowers are tasty to humans as well -- straight or soaked in cold water (but leave some for the ocotillo and other animals, and while you're at it, spread some pollen around to avoid being a cheat as well as a thief). Another use of ocotillos by humans is to make "living fences" by planting their branches in the ground.

WHAT'S UP WITH LIMESTONE?

Ocotillos are. Limestone rock stores (and then gives off during cold nights) more heat than most rocks, and limestone weathers into a thin soil, both of which favor desert-adapted plants at higher elevations. Indeed, "desert vegetation in general extends about 1000 feet (300 m) higher in elevation on limestone..." (ASDM 2000). Look for all the ocotillos growing on the hill on the left side of the road as you approach the mouth of Madera Canyon in the Santa Rita Mountains. In contrast, granite rock weathers into a spongy soil that retains moisture that allows plants to grow in lower elevation, drier areas than they would be able to on other soils.