Opuntia Blog

Dracaena cinnabara tree, image from Wikipedia, click on the image to see the original (large) image at Wikipedia

Dracaena cinnabari is not a cactus, but it is an amazing plant. D. cinnabari is endemic to Socotra Island in Yemen. Its common name, dragon blood tree, derives from the reddish sap obtained from the tree that is used as a dye or a medicine. Wikipedia reports that the red resin was used in dying wool, gluing pottery, as a breath freshener and as a lipstick. Purportedly, the red sap has been employed in magic rituals.

Some sources suggest that D. cinnabari was widely distributed over Socotra Island in the past, but while it is still widespread, it is in scattered populations. It is not clear why overall numbers of the tree have declined because Socotra Island is not yet subject to typical ecological pressures (eg, urbanization, ranching). The trees typicall grow “areas affected by the mists, low cloud and, in particular, the constant drizzle of the monsoon.” Perhaps such areas are not as common as in the past? One source reports that there is circumstantial evidence of drying in the region over the past few hundred years.

You can find out more about D. cinabari at the Arkive. 

Cactus Ferruginous Pygmy-Owl, photo by Norm Smith, click on image to see more of Mr. Smith's photographs

The cactus ferruginous pygmy-owlis one of three subspecies of ferruginous pygmy-owls. One subspecies is found in south Texas and into Mexico, and one is found in South America. The cactus ferruginous pygmy owl (Glaucidium brasilianum subsp. cactorum) is found in south-central Arizona and adjacent portions of Mexico. These small owls are 6-7 inches in length, and males weigh just over  2 ounces while females are a bit heavier.

The cactus ferruginous pygmy-owl typically nests in tree or cactus  (saguaro or organ pipe) cavities from about April to June. The birds are generally found below 4,000 ft in riparian woodlands or in grasslands and scrublands. They were listed as an endangered species but their legal status has changed in recent years. It is thought that urban sprawl, livestock ranching, or other factors (eg, noise and pollution) have contributed to the loss of habitat.

You can find more about the cactus ferruginous pygmy-owl at Owling.com or at the Arizona Game and Fish Department.

Xoconostle fruits, click image to see original advertizment

El Universal is a newspaper in Mexico. I don’t often read it, but sometimes I enter the URL into Google and then ask for a translation. It is interesting and fun to read about events in our large neighbor to the south (population about 110,000,000).

Recently I saw an advertisement for xoconostle in El Universal; xoconostle are a special type of Opuntia fruit. The fruits are sour (acidic) but wonderful in cooking. Additionally, the seeds cluster in the interior of the fruit; they are not dispersed as is the case for the fruits of many Opuntia species. Because they are clustered, they can be easily scooped out for fruit preparation. Xoconostle are only produced by a few Opuntia species (eg, O. matudae, O. oligacantha, O. leucotricha, and O. jonocostle). 

Xoconostle fruits can be used in many dishes from salsa, to jam, to hot dishes (even with beans), or breads. Often, xoconostle fruits are used in sauces or as condiments (even pickled). Xoconostle fruits are even used in beverages, sometimes with honey and lemon.

The Atacama Desert in northern Chile runs along the coast and extends inland to the base of the Andes Mountains; the desert is about 50-100 miles wide and about 600 miles in length. The Atacama Desert is one of the driest places on earth; it is estimated that some parts of the desert have not received rain for 300 years. The Atacama Desert has relatively mild temperatures (not as hot as other deserts, nor as cold). Rivers from the Andes Mountains cut across the desert at different places, taking their water to the Pacific Ocean.

Several Web sites provide stunning images of cacti in the Atacama Desert, including the site of Gerhard Hudepohl.

Though rain is scarce, a million or more people live in the Atacama Desert; they are mostly clustered along the Pacific Ocean coast and use rivers for their water sources. Fishermen and miners can be found in the various towns and villages.

Many parts of the Atacama Desert are too dry to support any plant life, but some areas receive a little rain each year. In some areas of the desert, ocean fog provides moisture for plants and animals. Closer to the mountains, there is more precipitation than is found in the center of the desert.

Unidentified cactus in the Atacama Desert, photo by Andrew Dunn

Cacti of the Desert Southwest, book

Amazon.com offers a seemingly endless supply of books. Recently, I purchased a small book called Cacti of the Desert Southwest. I paid just about $4.00 plus postage to purchase the book used from a bookseller. Sometimes the new book price is just too expensive, but other times Amazon.com offers a discount. But, the new book price seldom beats the used book price. I’ve had nothing but success when I’ve ordered used books–no problems and delivery has been within a week or two.

Cactus Candy

Cactus candy is a novelty that is offered by a few candy stores. If you are brave (and want to handle an Opuntia cladode), you can make your own candy.

RECIPE
Use a sharp knife to remove spines and epidermis from 1 or 2 large Opuntia cladodes. Cut the skinned cladode into squares (about one-half to one inch). Pour cold water over the squares and soak overnight in a large excess of water at room temperature. Change the water and gently simmer the  squares until they are tender. Drain the squares and heat slowly in the prepared syrup until most of the syrup is absorbed; drain the squares. Roll the squares in sugar (powdered or granulated).

Syrup
Dissolve 3 cups of sugar in 1 cup of water over low heat until sugar is completely dissolved. Add 2 tablespoons orange juice and 1 tablespoon lemon juice. Use red food coloring if desired.

You can read more about cactus candy here. You can order cactus candy at the Cactus Candy Company.

Opuntia stricta seedlings, photo by Danny Green

Cactus seedlings generally can’t endure the conditions that mature plants can take in stride. Seedlings are sensitive to too much heat, sun, wind, and cold, as well as lack of water. Additionally, seedlings are more susceptible to grazing by insects and animals. Most cactus seeds never produce a cactus plant; they may germinate but very few live to produce a mature plant.

Many factors affect seed germination including temperature, moisture, and mechanical scraping of the seed. But, germination is just one aspect in plant reproduction. Seedlings must be able to survive and reproduce. Likely, many cactus seedlings only survive when special years occur, years with extra water or mild temperatures. Probably two or tree such years in a row are necessary.

One study showed that one in 20,000 Opuntia rastrera seeds survives to produce a plant in a grassland setting. The success rate is even worse in scrublands where one in 7,000,000 seeds produces a plant.

Opuntia ficus-indica, proposed for fighting desertification

Opuntia are considered a weedy species in many countries where they are not native, especially in the Mediteranean, Africa, Asia, and Australia. The plants have overrun farmlands and degraded natural habitats. However, at least sometimes, Opuntia are considered allies in the fight against the spread of deserts.

A newspaper reports that,

“The Federal Government has recommended that “Cactus Opuntia” plant should be used to combat desertification in Nigeria, Minister of Environment Mr John Odey has said.

He made the statement on Tuesday in Abuja at a sensitisation workshop on the “Utilization of Cactus Opuntia to combat desertification, organised by Interact Safety System Ltd.He said that the plant was selected, due to its potential in erosion control and land rehabilitation, especially in the arid and semi-arid zones of the country.”

I guess that one man’s poison is another man’s food. Read more about the use of Opuntia to fight desertification here and here.

The photo in the blog post shows a cactus seedling, grown under fluorescent lights and about 3-4 weeks old. The cotyledons are reddish, and sort of pointed to the left or right. They are not the typical cotyledons of a radish or other plant, rather, they are much reduced. The seedling is tiny, about 4-5 mm tall.

The “real” cactus is tinier still and sits at the top of the seedling; it is the white, fuzzy bit between the cotyledons. In time, the white, fuzzy bit will grow and become the cactus we are more familiar with.

Lobivia seedling, 3-4 weeks old

Opuntia trichophora, north-central New Mexico, about 5,200 feet elevation

If you look in the seed catalog of SuccSeed Nursery, you can find some cacti from 3,000 or 4,000 meters in the Andes mountains. If you do the conversion, 4,000 meters is equal to abut 13,200 feet elevation, which is about 2 1/2 miles altitude.

Some of the Opuntia on this page were photographed by Daiv Freeman (CactiGuide.com) at about 10,500 feet in the White Mountains of California. Again, if you do the math, that is about 2 miles elevation. More commonly, cacti can often be found between 5,000 feet and 7,500 feet (1 mile to 1 1/2 miles high).

I think most cacti are found growing between sea level and several thousand feet, but there are a number of cold and dry areas of the New World where cacti can be found. The cacti may not be numerous or prolific, but they grow at amazing altitudes.

The various genera that include high-altitude cacti include Echinopsis, Opuntia, Rebutia, Lobivia, Pediocactus, Escobaria, Sclerocactus, Tephrocactus, and many more.

Stuart in the snow

I live in Maryland and, since leaving Texas, I haven’t had an outside garden. So, I grow cacti on my patio, or in the house under lights (in winter). Next year I hope to have a few more plants in pots that I can leave out for the winter (or most of the winter). 

We’ve had a lot of snow recently in Maryland, and it’s just as well I don’t have many plants outdoors because I wouldn’t be able to find them. There was about 2 foot of snow before Christmas, and recently another 30 inches. More snow is forecast for tonight.

I don’t have a photograph of cacti in the snow, but I do have a photo of my dog in the snow. He was happy to get into the house after the picture was taken. You can find actual pictures of cacti with snow here, and here.

Garden Soil

A brief discussion on a cactus email list recently got me thinking about potting soil for cacti: to sterilize or not to sterilize. This is a topic that stirs passions.

For what it’s worth, I don’t use sterile soils in my potting mix, but I use “clean” ingredients. Thus, for small amounts of soil I use packaged potting soil (typically a loam with compost) as a base. I mix the base with coarse sand and with perlite or pumice. For general use I add each part in equal volumes. Because I use packaged and/or composted ingredients, I don’t worry about insect eggs or fungal inoculum, and I don’t heat treat the ingredients.

However, if I used soil right from the garden (as in the photo) I’d be sure to bake it for 2 hours or more at 200 degrees F (about 93 C) to kill insects and some pathogens. If I threw in a handful of compost (from the compost pile) and I wouldn’t bother to heat treat the compost because I’m happy with the “cleanliness” of composed ingredients.

Other folks feel differently about the matter and don’t take special efforts to kill organisms in their potting soils, heating or composting. I guess that, whatever works for you is what you should do.

This lovely photo came labeled as Trichocereus formosus. So, my question is, what is the name for this plant when it is considered as a member of Echinopsis?

Note added later: Trichocereus formosus is known as Echinopsis formosa. However, a reader points out that the plant in the picture is probably a hybrid.

Unidentified Echinopsis

Tortoise, Texas (Gopherus species)

Cacti grow in many places, but often the surrounding country is beautiful and desolate. If you follow the link here, you can see some great images from the American Southwest. All the images feature cacti, or were taken near cacti.

What do all the following names have in common? Apparently all of them have been used at one time to describe Parodia, or a species of Parodia. That is a lot of names to go around for a genus of about 50 species. Read more about Parodia here.

• Acanthocephala
• Brasilicactus
• Brasiliparodia
• Brasilocactus
• Chrysocactus
• Dactylanthocactus
• Eriocactus
• Eriocephala
• Friesia
• Hickenia
• Jauhisoparodia
• Malacocarpus
• Microspermia
• Neohickenia
• Notocactus
• Sericocactus
• Wigginsia

Parodia herteri, image from Wikipedia

Monstrose Lophocereus schottii

Monstrose plants are not limited to cacti, but because of their normally limited morphology, monstrose cacti seem more remarkable and beautiful. The precise cause (or causes) of monstrose growth are unknown, but the results are appreciated.

Many monstrose (or cristate) cacti are not as strong as their “normal” counterparts. Thus, they are slower growing and sometimes more tender to drought and cold. However, the Lophocereus pictured here seems robust and happy.

You can learn more about monstrose plants here and here.

Cactus spines

Cactus spines are amazing. They come in so many shapes, colors, and sizes. It is hard to see, especially with all their variety, but cactus spines are modified leaves.

Cactus seedlings, click on image to see original photos (large size) at Flickr

Cacti are tough, and they can go months without water even in hot sun. Cacti are made to endure. But, it is a wonder how seedling cacti ever get started–they are tiny and dry out easily, and they don’t like hot sun.

For sure, many seeds germinate in the shade of their mother plant, or even in the shade of a shrub or a rock. The light is bright but not direct hot sun.

For water, it seems likely that most seedlings don’t germinate until there has been a fair bit of rain, and the soil is saturated with water. Even so it seems probable that most seedling cacti don’t make it, only those that germinate in “exceptional” years can survive. Exceptional years are those with extra rain and (perhaps) cooler temperatures. Some cactus might even need two exceptional years in a row.

However, that is not so unusual for plants that live many years. Cacti can survive for decades and if they only have “exceptional” years every 10 or 20 years then they’ll still have a chance for their seeds to germinate.

Melocactus peruvianus with cephalium, photo by Craig Howe

Some cacti have juvenile and adult growth, two distinct forms. Only adult growth can flower. The adult growth forms a cephalium, a very distinct region of the shoot, or an entire portion of the shoot. The cephalium is the adult growth that can flower.

Melocactus peruvianus is on type of cactus that has juvenile and adult growth forms. The cephalium of M. peruvianus is distinctive and forms after years of juvenile growth.

“Cephalium is a, frequently brightly coloured, structure of wool and bristle at the growing tip of certain cacti. It is most commonly found on cacti of the genus Melocactus and can take a number of colours, forms and shapes.”

Cut cactus showing callus, click image to read original article

I found a nice article about cuttings on the WWW. It has great photos of callused cacti, of agave proliferations, and cactus cuttings. The article also describes how to grow cacti and succulents from seed, but it is the photos of the cutting process that interested me.

You can access the article (with color photos) here.

Sample graft from article

The World Wildlife Fund has prepared an interesting article that you can read here. It is concerned with “Trade and Conservation of Chihuahuan Desert Cacti. The article describes plants in Texas, New Mexico, Arizona, and Mexico that are vulnerable to overharvesting. Even Opuntia are vulnerable because they are harvested unsustainably for use in cosmetics.

Most of us, as cactus growers, only grow seed-grown plants from reliable dealers, but a blackmarket trade continues across international and state borders.

“World Wildlife Fund (WWF) considers the Chihuahuan Desert Ecoregion (CDE) of Mexico and the United States an important ecoregion for conservation because of its outstanding biological diversity, ecological fragility, and environmental concerns. The ecoregion, rich in natural resources, faces a range of visible threats stemming from human activities such as mining, fossil fuel exploration, livestock grazing, industrial agriculture, and development.”

Cactus Climber for Cats

If you like cacti, and cats, this product may be for you. In any event, it is likely better than letting your cats climb a cactus. You can read about the product here.

“This attractive tree incorporates a 5-inch wide ledge within each of its 6 arms. The arrangement of these arms allows cats to climb up and down the tree. A wide base ensures that the unit will not topple over under normal circumstances.”

Outside of cactus flower showing the scaly leaves (click on photo to see original image at the Web site that describes the research of Dr. Maseuth, University of Texas)

Typically, cacti are considered to be leafless. This is because they’ve adapted their stems to do the work of photosynthesis (rather than leaves). But, cacti do have leaves after a fashion.

Little seedlings have primary leaves (cotyledons) and flowers very often have leaves on their outsides.

See the image (click on photo to see original image and a page about cactus flowers). It shows the outside of a cactus flower and the “scales” are modified leaves.

Learn more about cactus flowers here, and here.

The Cactus Cuties are Baylee Barrett, Blaire Elbert, Andi Kitten, and Madeline Powell, directed by Cami Caldwell. You can hear them sing the national anthem by clicking here.

You can find out more about the Cactus Cuties at their Web site.

The Cactus Cuties

Opuntia and model, click image to go to original Web page

If you Google for “Mickey Mouse” and “Cactus” you’ll find a lot of interesting photos; the same goes for “Mickey Mouse” and “Opuntia.” This is the best photo I found in a recent search. The photo comes from Lisa and Neil’s Big Adventure; they took a trip to the Galapagos Islands and put up a page describing what they saw.