Biocontrol of Opuntia Weeds

Prickly Pear Biocontrol

Video: Biocontrol of Opuntia in Kenya

(embedded from YouTube)


Video: Biocontrol of Opuntia

(embedded from Youtube)

Invasive Opuntia Weeds

Prickly Pear Weeds

Opuntia in Africa
Opuntia in Africa

Prickly pear cactus weeds are invasive and unwanted aliens in many environments. There is the potential for Opuntia invasion in many warm and dry parts of the world such as Australia and Africa. The most serious prickly pear weeds appear to be O. dillenii, O. stricta, and O. ficus indica, but other invasive Opuntia species are known as well as Cylindropuntia species. Though they have the potential to provide forage for animals and food for humans, opuntia plants can rapidly overrun disturbed areas such as croplands and pastures. They create impenetrable thickets that displace native plants. Animals are often injured when they feed on Opuntia cladodes and fruits.

An Opuntia infestation in Australia in the early 20th century was successfully controlled by the introduction of the cactus moth which fed on the prickly pears. Related biocontrol efforts are underway in parts of Africa, but these employ the cochineal insect. 


Video: Opuntia Invasion of Africa (Part One)

(embedded from YouTube)


Video: Opuntia Invasion of Africa (Part Two)

(embedded from YouTube)


Video: Opuntia Invasion of Africa (Part Three)

(embedded from YouTube)

Opuntias and Desert Survival?

Tortoise Eating Opuntia
Tortoise Eating Opuntia

Eating Prickly Pears

Opuntia species are ubiquitous in The West, occurring with great frequency in some areas. Prickly pears were used as food, medicines, and perhaps as awls by Native Americans and can still serve as food, either the pads or the fruits. These videos show how wild prickly pears can be prepared for consumption. One of the major challenges is to remove the spines, this is generally done with fire. 

Campers ready for a bit of the Old West can pick Opuntia pads or fruit and prepare them around a campfire, adding authenticity to a trip away from home. It is less clear how prickly pears can serve as survival food, but a video is included here to illustrate such an idea. Certainly, nopales are consumed throughout Mexico and Central America as a vegetable, but those plants are completely different from the wild opuntia species of the Southwest. For one thing, the nopales cladodes are nearly spineless at a young age, and whatever spines there are may be removed by expert scraping with a knife. Also, the young pads are flexible and not woody or hard. 

Nonetheless, the fruits of native prickly pears are valued by some people for their exotic nature and sweetness. Opuntia syrups and jams make excellent additions to other dishes. But, it is important to know which prickly pear to consume. For instance, the fruits of O. lindheimeri are nearly noxious, whereas the fruits of O. engelmannii are sweet. Also, old fruits from the past season may be hard and lack juice even while they are plump and red and look delicious. 


How To Campfire Cook Cactus Pads

(embedded from TouTube)


How to Pick and Eat Prickly Pear Fruit

(embedded from YouTube)


Desert Survival with Opuntias (?)

(embeddled from YouTube)

Health Benefits of Opuntia

Nopalitos with Rice and Avocado
Nopalitos with Rice and Avocado

Health Benefits of Prickly Pears

Opuntia (nopales) has many health benefits if you eat the pads or the fruits. 

Additionally, the plants will grow in arid climates and provide crop alternatives.

Health Benefits of Opuntia

(embedded from YouTube)


Food Security and Opuntias

(embedded from YouTube)


TOP 8 Surprising Health Benefits of Prickly Pears

(embedded from YouTube)


Prickly Pear Jelly

(embedded from YouTube)


Grafting Cacti Onto Opuntia Rootstock

Grafting with Opuntia
Grafting with Opuntia

Grafting with Opuntia

Some cacti naturally grow slowly from seeds. Some cacti do not produce offsets, making propagation difficult. Some cacti are subject to disease when grown on their own roots. Some cactus mutants are unable to photosynthesize because they don’t have chlorophyll. Some cacti are naturally very small. Some cacti don’t bloom well on their own. All of these problems can be solved with grafting. Grafting plants is a widespread practice in agriculture (e.g., grapes or fruit trees) where it can be difficult. Grafting cacti is particularly easy. 

Grafted Opuntia,
Grafted Opuntia,

Grafting involves the fusion of two components. Essentially all cacti can be grafted (fused together). They are compatible with one another. A shoot (scion) is fused with a rootstock (base of the graft). Thus, there is a top part of the grafted plant that is different from the base of the grafted plant. The rootstock is usually chosen to be a plant that grows well on its own roots and that photosynthesizes well. The scion may be any cactus, but is usually a cactus that benefits from a strong rootstock. 

Although many types of cacti are used as rootstock, one of the most common is an Opuntia. Several different Opuntia species are used including O. humifusa because it is a strong grower that is cold-tolerant and resists most diseases. Another rootstock is O. fragilis


Tubercles Grafted Onto Opuntia Rootstock

(embedded from YouTube)


Grafting Cacti onto Small Opuntias

(embedded from YouTube)

General Opuntia Topics

Grilled Nopales
Grilled Nopales

Opuntia topics

Opuntias are a vast and varied group. They grow on every continent except Antarctica. Prickly pears interact with animals and are used as animal fodder; are affected by the weather; are eaten for food, vitamins, and overall health; and even provide a red dye. These articles will help you find out more about opuntias. Prickly pears are important weeds in some dry areas such as southern Africa or Australia, but they are also managed as crops on some continents. 


Although you might think Opuntia names name would be simple, Opuntia or prickly pear cactus. It turns out that there are a multitude of names for just one Opuntia, O. ficus-indica, including: 

  • Barbary Fig, Cactus decumanus, Cactus ficus-indica, Cactus Flowers, Cactus Fruit, Cactus Pear Fruit, Figue d’Inde, Figuier de Barbarie, Fruit du Cactus, Fruit de l’Oponce, Indian Fig, Indian Fig Prickly Pear, Indien Figue, Nopal, Nopal Cactus, Nopales, Nopol, OPI, Oponce, Opuntia, Opuntia albicarpa, Opuntia amyclaea, Opuntia cordobensis, Opuntia decumana, Opuntia ficus, Opuntia ficus-barbarica, Opuntia ficus-indica, Opuntia gymnocarpa, Opuntia hispanica, Opuntia joconostle, Opuntia maxima, Opuntia megacantha, Opuntia paraguayensis, Prickly Pear, Spineless Cactus, and Tuna Cactus. 



General Information

Special Topics

Food and Medicine

Opuntia References

Opuntia oricola
Opuntia oricola


Multiple references were consulted during the construction of this prickly pear website–Opuntia Web. There are countless confusing references about cacti in general and opuntias in particular; there are often many names that refer to the same species of cactus. We worked our way through them to decide Opuntia names. Generally, we chose names that are associated with good descriptions or which are names of longstanding–or both. The names we chose provide a good starting place for the reader if they want to look up more names. For instance, O. humifusa was called O. opuntia by Britton and Rose, but this name fell into disuse. Later, it was called O. compressa, and this name fell into disuse. At one time in the early 1800s O. humifusa was known as Cactus humifusus. Perhaps any of these names could be used, but we chose O. humifusa

An important part of a plant name is the person who named it, and the journal and year it was published. For instance, the long-form name of O. humifusa is “Opuntia humifusa (Rafinesque) Rafinesque, Flora Medica (or Manual of the Medical Botany of the United States of North America) 2: 247, 1830.” This long name tells you that the author was Constantine Samuel Rafinesque. The name was published in Flora Media, volume 2 on page 247 in 1830.  

Names make a difference. If you use O. humifusa, you will never find the writings about Cactus humifusus and you will miss important information. We present some of those references here so you can consult them for yourselves. You may decide to choose a name that we passed over, but these resources will help you find other names. 

On the other hand, for just gardening and enjoying plants, names are not so terribly important. O. humifusa is also known as O. compressa and most Opuntia growers know they are the same plant. Sometimes people describe a plant with a name such as, “the cactus from my grandmother that has yellow flowers.” This is fine for informal purposes. 

If you want more information, consult the resources listed here.  We also hope you will write to us if you have questions about names or for any other reason. Perhaps you will have a suggestion about a better name choice than we made. 

See in this Website


DNA, Reproduction, and Ecology

How Species Are Identified

Other Sources

A Dictionary of Botany, Little, RJ and Jones, EU, Van Nostrand Reinhold Co, 1983

Biodiversity Heritage Library, Website

Botanicus, Website

Cacti & Other Succulents of Arizona (Field Guide to), Breslin, P et al, Tucson Cactus and Succulent Society,  2015

Cacti of Texas and Neighboring States, Weniger D, University of Texas Press, second ed, 1988

Cacti of the Southwest, Del Weniger, University of Texas Press, 1978

Cacti of the Trans-Pecos and Adjacent Areas, Powell MA and Weedin JF, Texas Tech University Press, 2004 

Cacti, Agaves, and Yuccas of California and Nevada, Ingram, S, Cachuma Press, 2008

Cacti, Biology and Uses, Park S Nobel (ed), 2002, University of California Press

Cactiguide, Website

Cactus and Succulent Digital Library, Website

Chromosome Counts Database, Website

Field Guide to Cacti & Other Succulents of Arizona, Breslin et al., 2015

Flora of North America, Website

Index to Plant Chromosome Numbers, Website

Opuntia toumeyi
Opuntia toumeyi

Opuntia at American Southwest, Website

Opuntia at Encyclopedia Britannica. Website

Opuntia at Encyclopedia of Life, Website

Opuntia at Gardenia Net, Website

Opuntia, at Wikipedia, Website

Pricklypears commonly found in the United States and northern Mexico, Green, C with Ferguson, D, 2012

The Cactaceae: descriptions and illustrations of plants of the cactus family, NL Britton and NJ Rose, Carnegie Institution of Washington, volume 1, 1919

The Cactaceae: descriptions and illustrations of plants of the cactus family, NL Britton and NJ Rose, Carnegie Institution of Washington, volume 2, 1920

The Cactaceae: descriptions and illustrations of plants of the cactus family, NL Britton and NJ Rose, Carnegie Institution of Washington, volume 3, 1922

The Cactaceae: descriptions and illustrations of plants of the cactus family, NL Britton and NJ Rose, Carnegie Institution of Washington, volume 4, 1923

The Cacti of the United States and Canada, Benson L, Stanford University Press, 1982

The Cactus Family, Anderson, E, Timber Press, 2001

The New Cactus Lexicon (text volume), Hunt with others, 2006

The Plant List, Website

The Succulent Plant Page, Website

Trees, Shrubs & Cacti of South Texas, Everitt, JH and Drawe, DL, Texas Tech University Press, 1993

Tropicos, Website

…and many other sources



The Cactaceae: Descriptions and Illustrations of Plants of the Cactus Family was provided courtesy of the Cactus and Succulent Digital Library The PDF copy that we use has been pass through optical character recognition and manually checked. Our thanks to the CSDL. 


Opuntia DNA


Opuntia DNA and Ploidy

An index to published chromosome information many cacti and prickly pears is at Index to Plant Chromosome Numbers (IPCN, Tropicos). Another index to many plants is at Chromosome Counts Database, Rice et al., 2016, Website. 

Ploidy information for many Opuntia species of the USA may also be found in “Pricklypears Commonly Found in the United States and Northern Mexico”, Green, C with Ferguson, D, 2012 (ISBN: 0615131212, 9780615131214). Another excellent source of ploidy information for cacti is “Cacti of the Trans-Pecos and Adjacent Areas”, Powell and Weedin, 2004 (ISBN: 0896725316, 978-0896725317). 

Prickly pear names change, and new science provides new evidence. Ploidy levels and taxonomy as presented here represent the best knowledge available at the time the various materials were published. Some species were undoubtedly misidentified. Names of opuntias have changed over time, thus it is important to interpret this information carefully. 


A Cytological and Morphometric Analysis of a Triploid Apomict, Opuntia ×kelvinensis, Baker and Pinkava, 1987

An Intron Loss in the Chloroplast Gene rpo C1 Supports a Monophyletic Origin for the Subfamily Cactoideae of the Cactaceae, Wallace and Costa, 1996

Opuntia of North America, An Overview, Rebman and Pinkava, 2001

Chromosome Counts of Miscellaneous Cacti, Ferguson, 1991 (unpublished)

Chromosome Counts of Opuntia (Cactaceae), Prickly Pear Cacti, in the Midwestern United States, Ribbens and Majure, 2012

Chromosome Counts, Cytology, and Reproduction in the Cactaceae, Ross, 1981

Plant Cell Nuclei
Plant Cell Nuclei

Chromosome Numbers for the Flora of Organ Pipe Cactus National Monument, Pinkava et al., 1992

Chromosome Numbers, Nuclear DNA Content, and Polyploidy in Consolea, Negron-Ortiz, 2007

Chromosome Numbers in Chihuahuan Desert Cacti, Weedin and Powell, 1978

Chromosome Numbers in Chihuahuan Desert Cacti II, Weedin et al., 1989

Chromosome Numbers in Chihuahuan Desert Cacti III, Powell and Weedin, 2001

Chromosome Numbers in Cacti of Western North America I, Pinkava and McLeod, 1971

Chromosome Numbers in Cacti of Western North America II, Pinkava et al., 1973

Chromosome Numbers in Cacti of Western North America III, Pinkava et al., 1977

Chromosome Numbers in Cacti of Western North America IV, Pinkava and Parfitt, 1982

Chromosome Numbers in Cacti of Western North America V, Pinkava et al., 1985

Chromosome Numbers in Cacti of Western North America VI, with Nomenclatural Changes, Pinkava et al., 1992

Chromosome Numbers in Cacti of Western North America VII, Pinkava et al., 1998

Chromosome Numbers in Cacti of Western North America VIII, Baker et al., 2009

Chromosome Numbers in Miscellaneous North American Vascular Plants, Parfitt et al., 1990

Chromosome Numbers of Some of the Cactaceae, Stockwell, 1935

Club Chollas of the Big Bend, Fenstermacher, 2016

Cylindropuntia chuckwallensis, Baker and Cloud-Hughes, 2014

Cylindropuntia multigeniculata, Baker, 2005

Cytogeography of the Humifusa Clade of Opuntia, Majure et al., 2012

Documented Chromosome Numbers, 2005, trans-Pecos, Weedin and Powell, 2005

Fruit Characters Among Apomicts and Sexual Progeny of a Cross of the Texas Native Opuntia lindheimeri (1250) with a Commercial Fruit Type Opuntia ficus–indica (1281), Felker, et al., 2009

Genome Sizes and Ploidy in Mexican Species of Opuntia, Segura et al., 2007

Grusonia pulchella classification and its impacts on the genus Grusonia, Griffith, 2002

Isolation and Characterization of Polymorphic Microsatellite Markers in Galapagos Prickly Pear Cactus Species, Helsen et al., 2007

Low Levels of Genetic Differentiation between Opuntia echios, Helsen, et al., 2009

Karyotypes, Heterochromatin, and Physical Mapping of 18S-26S rDNA in Cactaceae, Penas, et al., 2009

Karyotpic Studies in (three species) of Opuntia, Palomino and Heras, 2001

Plant Chromosomes
Plant Chromosomes

Karyotypes to Determine Relationships between Species of Opuntia, 2000

Measuring Genome Size of Desert Plants Using Dry Seeds, Sliwinska et al., 2009

miRNA Expression During Prickly Pear Cactus Fruit development, Caballero et al., 2015

Miscellaneous Chromosome Numbers in Opuntieae, Majure et al., 2012

Molecular Based Assessment of Genetic Diversity of xoconostle Accessions, Valadez-Moctezuma et al., 2014

Molecular Based Assessment of Genetic Diversity Within Barbary fig, Zoghlami et al., 2007

Molecular Characteristics of Prickly-pear Cactus (Opuntia) Based on Internal Transcribed Spacer Sequences (ITS) of Queretaro State – Mexico, de Lyra et al., 2012

Molecular Phylogeny and Character Evolution in Terete-stemmed Andean Opuntias, Ritz et et al., 2012

Molecular Studies of Forage Prickly-pear Cactus from Brazil, Catanho Pereira de Lyra, 2015

Molecular Systematics of the Cactaceae, Barcenas, et al., 2011

Multivariate Analysis of Karyotpes in Opuntia, Bandyopadhyay and Sharma, 2000

Natural Pentaploids in the Opuntia lindheimeriphaeacantha Group in Texas, Grant and Grant, 1982

Nomenclatural Changes in Cylindropuntia and Opuntia, Pinkava, 2002

Nuclear DNA in Angiosperms, Bennet and Leitch, 2010

Números Cromosomáticos Para las Cactaceae del Paraguay, Author and date unknown

Opuntia delafuentiana a New Xoconostle from Central Mexico, Martinez-Gonzalez et al., 2015

Plant Cell Walls
Plant Cell Walls

Opuntia diploursina, Stock et al., 2014

Opuntia ficus-indica; Chromosome Races and Origins, Tephrocactus Study Group, Rowley

Origins of Opuntia curvospina, Parfitt, 1980

Phylogenetic Relationships in Opuntia (Cactaceae, Opuntioideae) from South America, Realini, 2014

Phylogeny of Opuntia ss–Clade delineation, geographic origins, and reticulate evolution, Majure et all, 2012

Taxonomy and  Distribution of Opuntia and Related Plants, Puente and Pinkava, date unknown

The Origins of an Important Cactus Crop, Opuntia ficus-indica, Griffith, 2004

Typifications and a Nomeclatural Change in Some Eastern North American Opuntia, Majure, 2014

Using Molecular Data to Elucidate Reticulate Evolution in Opuntia (Cactaceae), Griffith, 2003

What Did the First Cacti Look Like, Griffith, 2004

Opuntia Artist: LCC Krieger

LCC Krieger
LCC Krieger


Louis Charles Christopher Krieger (1873-1940)  worked with David Griffiths at the Plant Introduction Garden in Chico, California. Griffiths was interested in the forage potential of prickly pear cacti (Opuntia spp.). 


Krieger painted a large series of species and forms of Opuntia between 1912 and 1917 for Griffith’s studies. These paintings are in the collection of the Department of Botany, Smithsonian Institution. They are watercolor over light photographic prints (black and white). The attention to anatomical and morphological detail is exquisite. 

Krieger painted many cacti, and his work is found in The Cactaceae, an important series by Britton and Rose. Though he is featured here for his Opuntia paintings, he is best known for his depictions of fungi. 

Opuntia Artist: Mary Emily Eaton

Mary Emily Eaton
Mary Emily Eaton


Mary Emily Eaton (1873-1961) was born on 27 November 1873 in Coleford, Gloucestershire, England.  She is best known as a botanical artist for her illustrations in The Cactaceae (Britton and Rose, 1919-1923) for which she was the principal illustrator.


She was employed by the New York Botanical Garden from about 1911 to 1932. Her illustrations are housed at the National Geographic Magazine and in the Contributions from the U.S. National Herbarium. These drawings of various opuntiads are from The Cactaceae, v1. Full-size drawings are available at Plant Illustrations.