The Unusual Ocotillo

Big Bend is home to many unusual, or some would say downright bizarre, plants. Many of them lie unnoticed or overlooked for much of the year unless you know what to look for. The well-named living rock cactus blends almost invisibly into the limestone hills around the park, but bursts into bold pink bloom in the early fall and is easily spotted then. Little gray-brown resurrection plants look like dead plant remains from last year until a good rain allows them to uncoil the vibrant, deep green leaves they have been protecting in a tightly curled ball during the dry times. Not all of the unusual plants blend into the desert landscape and go unnoticed though.

One Of The Oddballs

Ocotillo is one of the most conspicuous plants across the park, and definitely one of the oddballs in many respects. Ocotillo (pronounced “Oh-co-TEE-yo”) is also called coachwhip or candlewood or even vine cactus, and it is quite common on the gravelly slopes or flats driving to Rio Grande Village on the east side of the park or to Old Maverick Road on the west. At first glance, Ocotillo looks like a large shrub that died - just a cluster of drab, gray stalks covered in sharp half inch spines, and no obvious signs of life like leaves along the branches. The stalks may number only 2 or 3 in a cluster, or there may be well over a dozen in larger individuals, and the stalks may extend 20 to 30 feet into the air!

Survival Strategy

This bare bones appearance is actually part of ocotillo’s desert survival strategy. Plants lose most of their water through the thin, flat leaves during photosynthesis. Ocotillo and several other desert plants, notably the cacti, have adapted to desert life by moving the photosynthesis into their stems. The photosynthesis here is not as efficient or as productive as in typical plants, but the plants do save a lot of water and that is the principal issue for a desert dweller. Leaves are either not produced, or only produced during wet times of the year when the water losses are affordable to the plant. Ocotillo in Big Bend will often form slender one or two inch leaves four or five times per year shortly after a good rain, and then drop them after two or three weeks as drier conditions return. For those few weeks it is one of the most attractive plants in the park and a visitor favorite.

The real surprise though is in the spring when seemingly “dead stalks” of ocotillo burst into bloom. Slender clusters of bright red orange, tubular flowers form at the ends of the stalks, and in areas with abundant ocotillo plants it can look like a red haze is hanging just above the plants from a distance! The area around Old Maverick Road is a good place to see this in late March or April. These flowers are a favorite of carpenter bees and hummingbirds in Big Bend, and though the hummers get much of the credit as pollinators, it’s the bees that do most of the work.

Ocotillo is not a cactus as some think. It is a member of a small, unrelated family of primarily South American plants, of which it is the northernmost representative. It is found across the Chihuahuan and Sonoran deserts of Texas, New Mexico, Arizona, and a small part of California.

Ranger Jimmy Duke