Cacti Part 2 ~ Prickly Pears

The Opuntiodeae

Not so very long ago, all cacti were just that – cacti. Sure, there were various tribes, but still, all was one big family. Alas, this is no longer the case. Those uppity Opuntia’s have gone and gotten themselves elevated to the status of “subfamily.” Admittedly it’s a big subfamily – around 180 species – and like any family, its members are varied and diverse. Opuntias are distributed world wide, some naturally, but many were helped by humans who carried them (at least the Prickly Pears) everywhere they went. Prickly Pears have been cultivated for centuries as both the pads and the fruits are edible and nutritious.

It’s easy to tell if a cactus is an Opountiodeae. Opuntias grow a unique type of spine, called a “glochid.” Glochids are very small and numerous, usually straw-colored, and they surround the larger spines on the surface of the areole.

IMG_0337-glochids

The glochids in this picture are huge relative to glochids in other members of sub-family. The following picture shows a plant with average-size glochids.

IMG_3861-68

Glochids are equipped with microscopic barbs. They easily penetrate the skin, but because of the barbs, they are almost impossible to remove completely. They are intensely irritating.

Glochid barbs

All the Opountiodeae in this area of the Chihuahuan Desert produce yellow flowers, though the tepals of some may tend towards orange or pink. The flower buds are ovoid in shape, and otherwise look like other stems of the plant. The stems surfaces range from smooth to low tuberculate. Here in the south counties, they are all glaborous.

Three genera make up the Opountiodeae.

Opuntia

The word Opuntia was formerly used for all the Opuntias. Now, Opuntias are the plants we  know as Prickly Pears. The taxonomy of the Opountiodeae is not well understood, so for this discussion I am dividing them into two groups – green ones and purple ones.

The green Prickly Pears are simply that – green – always. Three of the green Prickly Pears are common in this area: Camanchica, Englemann’s, and Rufida. In some areas there may be O. Dulcis as well.

Engleman’s Prickly Pear

Englemann’s Prickly Pear is widely distributed throughout the state of Texas, and surrounding states. In size and growth habit it is extremely variable, but the bird’s foot spines distinguish it from other species, at least a little. Englemann’s Prickly Pear can grow quite large in good conditions. As such, it is the largest Opuntia species in the Trans Pecos. The flowers are all-yellow unlike the Comanchica Prickly Pear which has red centers.

Opuntia engelmannii

Comanche Prickly Pear

This cactus resides only in the hottest parts of the desert along the Rio Grande. It’s most distinguishing feature is the fact that its fruits have few or no spines near the apex. Also, they remain succulent long after ripening.

A prickly pear cactus (Opuntia) with fruit at the Airport

Comanche Prickly Pears are usually no more than a foot or so in height, but they can grow to 4½ feet in good conditions. The pads are usually broadly obovate to almost circular. They usually have spines on the distal third of the pad with 3 to 7 spines per areole but that is not a reliable way of identifying them as their spination varies significantly. The flowers are yellow with red centers.

O. Camanchica is an attractive cactus when in bloom as this photo taken by Richard Reynolds shows.

7150438361_c6b9d94324_h-1

Blind Eye Prickly Pear

This cactus (Opuntia rufida) is living at the extreme northern edge of its range and it is not known to live anywhere outside of the Big Bend Region. It is easy to identify as it has no spines at all – only glochids … but it has them in abundance. These glochids are only loosely attached to the plant, and can be dislodged by wind. The plant gets its popular name “Blind Eye” Prickly Pear from these loosely attached glochids. Airborne glochids can blind cattle.

_MG_0900-Opuntia rufida

Blind Eye Prickly Pears are particularly showy when blooming as they usually sport two different colored flowers in the spring. Some of the flowers are all yellow. Others are a beautiful peach color.

Purple Prickly Pears

The Purple Prickly Pears present us with a problem. For one thing, their taxonomy is not clearly understood at all, so botanists are forever switching them around as new information about their relations becomes available. This is just a fancy way of saying that you never know what one of these plants will be named tomorrow. Difficult…

In the past we simply called them “Purple Prickly Pears” and if they weren’t all that purple, we called them “Purple-Tinged Prickly Pear.” Now these groups have been further subdivided but the distinctions are not very clear in the wild, and what with the plant’s tendency to hybridize with other close relatives, accurate identification becomes problematic, so for the Purple Prickly Pears we will stick to common, popular names.

More difficulties arise from the fact that all the Purple Prickly Pears are extremely variable. The same species (or what is believed to be the same species), can sport gigantic spines, or practically none at all. They may be blue all over, or blue with purple edges and areoles, or purple all over, or even red. The pigment responsible for the color is commonly used by all the Prickly Pears, and other cacti as well, as a protection against severe dehydration, excessive sun, extreme cold, or simply on the whim of the plant, so you can’t rely on a purple prickly pear actually being a true Purple Prickly Pear.

The most noticeable Purple Prickly Pear is Opuntia macrocentra although even this one has been split out and placed in the diplopurperia group. This plant is usually simply called the Purple Prickly Pear. The pads are more red than purple, even when growing conditions are ideal. Because of its color, this plant is easily spotted at a distance.

_MG_9429-O-macrocentra

In bloom, it produces striking yellow blossoms with red centers. The fruits are smaller than most other species, but they are also sweeter.

_MG_6218-Opuntia macrocentra

The less distinctive Purple Prickly Pear is the “Purple Tinged” or “Purplish Prickly Pear.” It always has some purple, and when conditions are particularly favorable, the skin may take on a bluish hue. The one in this picture has purple around the edges and around the areoles.

_MG_5253 Purplish Prickly Pear

Another “Purplish Prickly Pear” is the Opuntia azurea var parva. It is usually smaller, and paler than its relatives, so it creates a lovely patch of pastel colors in a scene. In this picture you can see the vestigal leaves that appear on new pads of an Opuntia. They are the little upward pointing soft-looking “horns” on this new growth.

Opuntia azurea var parva

Of course there are many, many more species of Prickly Pears in the Big Bend Ranch State Park and the Big Bend National Park, and there are so many hybrids that counting is impossible, but you will probably often see these plants during your walks in the Big Bend.

In the next posting I will cover the other members of this sub-family … the ones we usually call “Chollas.” That post will probably be more strictly accurate than this one but who knows? If you have any corrections to offer, please do. I’d like these posts to be as accurate as possible.

So until then, don’t forget to hug your cacti 🙂

About aneyefortexas

Retired writer/teacher/photographer, now photographing the Chihuahuan Desert at the Big Bend Ranch State Park, Texas.
This entry was posted in Big Bend Ranch State Park, cacti, General Topics, Plants, Texas. Bookmark the permalink.

7 Responses to Cacti Part 2 ~ Prickly Pears

  1. Pingback: 2 Cleburne boys take on Rattler in a Cactus Dig ⋆ danbodine.com

  2. I always thought of Comanche Prickly Pear as a separate species, related to O. macrocentra. I see them in the foothills around El Paso, on the southern high plains into far SE Colorado, and SW into the Sandia foothills by ABQ. They flower similarly and at about the same time as O. macrocentra, also get purple in cold weather, but the pads are thicker and have more spines throughout…O. macrocentra tend to have most spines on the pads’ tops, and longer spines at that.

  3. selfring says:

    Great post Gary and thank you for your ID help with the icicle cholla.

  4. Roger Siglin says:

    I always enjoy your articles. Have you ever done one on creosote bush? I read years ago that it originated in Chile or Argentina and brought a sample back from Argentina. How and when it got to north america is attributed to birds.

    >

  5. White, John M says:

    Gary:

    Great job as usual, both written and visual. You always take such great photos!
    Hope you are doing well. Take care.

    John

    John White
    Chihuahuan Desert Gardens

    Sent from my iPhone

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s