Plants of Southern California: Chollas

Old and New Latin Names
Key to Chollas of Anza-Borrego State Park
Links to Pictures of Chollas of Anza-Borrego State Park


Cacti have been a thorn in the side of botanists for a long time, with names and taxa coming and going, and coming back again. Our understanding of cacti improved substantially when botanists began looking at the flowers, especially the color of the filaments and styles, to separate species, instead of using difficult characteristics such as the flatness and color of the spines.

This page collects the current recognized taxa for chollas, with a synonymy table for their names and a distribution table, and gives an updated key to the chollas of Anza-Borrego Desert State Park that includes the taxa missing from the Jepson Manual.

The taxa recognized here are the ones accepted at the Jepson Online Interchange as of 11 November 2003. This is different from the taxa recognized in the JM, but is equivalent to the ones recognized in blue Munz except for treating two varieties in Munz as a single species without varieties.

The synonymy table gives the translation to the names used in the Jepson Manual and (blue) Munz 1974, A Flora of Southern California. The names in Munz are identical to the names in Benson, The Native Cacti of California.

The first section below gives the taxa and the translations. The next section gives the distribution information for each species. The final section gives a key to the chollas of Anza-Borrego State Park. This is essentially the only place where one needs a key that includes the two taxa excluded from the JM key.

This page was significantly revised on 12/9/05, after finding on 12/6/05 that the specimen in front of the Anza-Borrego Desert State Park Visitor Center, formerly labeled O. echinocarpa from at least March 2003 through March 2005, was now labeled O. ganderi. For the revisions, I thank Jon Rebman for an extensive discussion about these two easily-confused chollas and about O. wolfii and O. acanthocarpa var. coloradensis, for information on the distribution of chollas in San Diego County, as well as for pointing me to the Flora of North America treatment of chollas that appeared after I first wrote this page.

Old and New Latin Names

In the table, I omit the author names to avoid making the table hopelessly unreadable. The authors for the old names are given in JM and Munz. The authors for the new names can be obtained from the Jepson Online Interchange, with the exception of Grusonia parishii. Its full name is Grusonia parishii (Orcutt) DJ.Pinkava (reference: The Confusing Names of California Cacti).

Scientific NameJM NameMunz / Benson NameNew Scientific NameComments
Opuntia acanthocarpa var. coloradensisOpuntia acanthocarpa var. coloradensisOpuntia acanthocarpa var. coloradensisCylindropuntia acanthocarpa var. coloradensis 
Opuntia acanthocarpa var. major-Opuntia acanthocarpa var. majorCylindropuntia acanthocarpa var. major 
Opuntia bigeloviiOpuntia bigeloviiOpuntia bigelovii var. bigeloviiCylindropuntia bigelovii; Cylindropuntia bigelovii var. bigelovii 
Opuntia echinocarpaOpuntia echinocarpaOpuntia echinocarpa var. echinocarpaCylindropuntia echinocarpa 
Opuntia fosbergii, O. XfosbergiiOpuntia XfosbergiiOpuntia bigelovii var. hoffmanniiCylindropuntia x fosbergiiThis is speculated to be C. bigelovii X C. echinocarpa, but there is no evidence yet presented that these are direct hybrids. This seems a perfectly-valid species in the field, no different from any of the other species without an "X" in their name.
Opuntia ganderi-Opuntia acanthocarpa var. ganderiCylindropuntia ganderionly mentioned in JM under O. parryi as "O. echinocarpa X O. parryi", which is no longer thought to be correct. See Rebman, 2005, Gander's Cholla: Our Common But Barely Known Cactus, in the Anza-Borrego Desert Natural History Association's The Sand Paper, 34, Issue 2, p. 3.
Opuntia XmunziiOpuntia XmunziiOpuntia munziiCylindropuntia x munzii; Cylindropuntia munziiThe hybrid status of this taxon is unclear
Opuntia parishiiOpuntia parishiiOpuntia stanlyi var. parishiiGrusonia parishiinew latin name not adopted at jepson interchange
Opuntia parryiOpuntia parryiOpuntia parryi var. parryi
Opuntia parryi var. serpentina
Cylindropuntia californica var. parkeri
Cylindropuntia californica var. californica
the two varieties in Munz / Benson have been combined into the single species in the JM; but have been retained as separate taxa in the Flora of North American Treatment.
Opuntia proliferaOpuntia proliferaOpuntia proliferaCylindropuntia prolifera 
Opuntia ramosissimaOpuntia ramosissimaOpuntia ramosissimaCylindropuntia ramosissima 
Opuntia wigginsii-Opuntia wigginsiiCylindropuntia x wigginsiiThis taxon is only mentioned in JM under O. ramosissima as "possibly O. ramosissima X O. echinocarpa".
Anderson (2001; The Cactus Family) subsumes this into Cylindropuntia acanthocarpa, but doesn't modify the stem diameter of C. acanthocarpa to include diameters < 1 cm. However, the Flora of North America (2003) treats this as just a depauperate form of Cylindropuntia echinocarpa.
Opuntia wolfiiOpuntia wolfiiOpuntia echinocarpa var. wolfiiCylindropuntia wolfii 


The general ranges defined by the vouchers plotted in Benson are roughly the same as the ranges plotted in the Flora of North America except for a few taxa such as O. bigelovii. However, one should be careful of deducing abundance information from the density of Benson's locations, since collections are non-uniform and any comparisons are rendered insignificant due to small number statistics.

For example, in the Borrego Valley, Benson gives 2 vouchers of O. wolfii, 2 vouchers of O. echinocarpa, and 2-3 vouchers of O. ganderi. One might naively conclude that these taxa are all equally abundant there, yet the most common species there of these three is O. ganderi by at least a factor of 10 to 100.

Probably also due to small number statistics, Beauchamp (1986) give the wrong distribution impression for these taxa in San Diego County:

The Beauchamp distributions are correct for O. parryi and approximately correct for O. wolfii. Beauchamp omits O. acanthocarpa var. coloradensis, but that is close to correct as well, since it is only found in the extreme northeast end of the county.

The San Diego County distribution information given here is from Rebman (private communication, 12/8/2005).

See also more detailed information about the distribution of O. echinocarpa, O. ganderi, O. parryi, and O. wolfii in San Diego County, including a detailed map of all locations known to me.

Latin NameCommon NameDistribution MapsDMojDsonOtherUn-
Opuntia acanthocarpa var. coloradensisbuckhorn chollaFNA11  Found only in narrow corridor along Colorado River, possibly to extreme northeast corner of San Diego County (Rebman).
Opuntia acanthocarpa var. majorbuckhorn chollaFNA  near Vidal Junction, e. San Bernardino County1The Flora of North America treatment didn't recognize this taxon as being in California. The California report is from Benson, who reported Vidal Junction as being in Riverside County, also given in Munz, and this is currently accepted by the Jepson Interchange as being in California pending verification of a voucher.
Opuntia bigeloviiteddy-bear chollaFNAse1  The Flora of North American distribution map shows a much more restricted range than the actual distribution. For example, O. bigelovii is locally common in Borrego Valley at the extreme west end of DSon, and Benson's plotted vouchers are almost entirely from the w DSon.
Opuntia echinocarpasilver chollaFNA;San Diego County11  Rebman: uncommon in San Diego County except in low dry areas. It is common along S2 in Imperial County.
Opuntia fosbergii (O. Xfosbergii)pink teddy-bear cholla  sw (e San Diego County)  occurs southwest of the Salton Sea, California
Opuntia ganderiGander's chollaFNA; San Diego County w  Rebman: The most common cholla in the Borrego Springs area and throughout Anza-Borrego Desert State Park, especially along the entire length of S2 north of Ocotillo and south of Scissors Crossing.
Opuntia XmunziiMunz's chollaFNA Chocolate and Chuckwalla Mnts, Imperial and Riverside counties. 1 
Opuntia parishiimat chollaFNAe & s  1 
Opuntia parryisnake chollaFNA; San Diego County w edgeSW (exc ChI)  
Opuntia proliferacoast chollaFNA  SCo, ChI  
Opuntia ramosissimapencil chollaFNA11   
Opuntia wigginsiiWiggins's cholla 1   on the very arid flats along the lower Colorado River in California and Arizona
Opuntia wolfiiWolf's chollaFNA; San Diego County w edge  Rebman: found most commonly along the Mountain Springs grade on I-8 at the border of Imperial and San Diego Counties.

Key to Chollas of Anza-Borrego State Park

This key has been modified from the JM, Munz and Flora of North America keys to key out just those chollas found in Anza-Borrego Desert State Park, and has been further modified from my fieldwork. The key is not generally valid elsewhere, since it doesn't include taxa found elsewhere.

See also Pictorial key to Opuntia echinocarpa, O. ganderi, O. parryi, and O. wolfii, and Opuntia bigelovii and O. fosbergii.

1 Fr spineless (sometimes with a few deciduous bristles)

2. Tubercle length ~ width - common, widespread ...................................................................................O. bigelovii
2'. Tubercle length ~ 2 x width - occasional, Box Canyon, Vallecito Wash, Canebrake Canyon .................O. fosbergii (O. Xfosbergii)
1' Fr with spines
3. Fr sparsely spiny to densely spiny; sts gen not obscured by spines; maximum st segment length 14-43 cm, western Park boundary in San Felipe / Earthquake Valley and Campo / Jacumba area ...... O. parryi
3'. Fr densely spiny; young sts gen obscured by spines; maximum st segment length 5-30 cm
4. St < 1 cm diam, tubercles < 2 mm high
5. St nearly covered with low flat platelike tubercles; spines solitary or absent - occasional, widespread.....O. ramosissima
5'. St with simple tubercles; spines more than 1 - rare, Canebrake Canyon .......O. wigginsii (probably an erroneous identification; not in latest San Diego County checklist)
4'. St > 1.5 cm diam, tubercles > 3 mm high
6. Filaments red to magenta
7. Filaments red; inner tepals bright yellow; trees or sometimes shrubs, with few branches, usually at acute angles, without strongly ascending branches; terminal stem segments 2-2.5(-3) cm diam.; tubercles (1.5-)2-3 cm - rare, only in extreme northeast corner of Park (Travertine Palms) .......... O. acanthocarpa var. coloradensis

7'. Filaments dark bronze-red to magenta; inner tepals yellow-green, suffused bronze to pale purple-brown; essentially low dense shrubs, usually with strongly ascending branches; terminal stem segments 2.5-4 cm diam.; tubercles 1-1.5(-2) cm - locally common in southwest corner of Park (e.g., San Felipe Valley, below Sentenec Canyon, Vallecito Canyon, Mountain Springs grade, Jacumba) ....... O. wolfii

6'. Filaments greenish-white to yellow to green, sometimes suffused with bronze or rose, but not red
8. Major branches strict, ascending; terminal stem segments usually 10-26 cm; stem tubercles usually 1.3-2.6 cm; inner tepals greenish yellow, often with tips reddish abaxially - common on western end of Park (w Borrego Valley, s Earthquake Valley, Vallecito Wash), above ~1000 feet elevation ............. O. ganderi

8'. Major branches spreading; terminal stem segments usually 3-7.5 cm; stem tubercles usually 0.4-1.5 cm; inner tepals yellow, green to yellowish green, or reddish maroon - uncommon, restricted to low drier areas, below ~1000 feet elevation ................... O. echinocarpa

The last four species in the above key require observations of the flowers to properly separate them. Unfortunately, those species generally bloom in April - June, and most botanists would like to id these species during the January - March time they are in the desert. If you like to live dangerously, here is a key to three of those four species using non-flower characteristics. (The fourth species, O. acanthocarpa var. coloradensis, is only found in the extreme northeast corner of the Park, and hence is not present in most places here). Any identifications made with this key should be confirmed using flowers!

See also Pictorial key to Opuntia echinocarpa, O. ganderi, O. parryi, and O. wolfii which gives photographs illustrating this key, along with locations for these species.

1. Major branches spreading; st segments 3-7.5 cm, diameter 1-2.5 cm ..... O. echinocarpa

1' Major branches ascending to strictly erect; st segments 6-40 cm, diameter (1.7) 2.5-4.5 cm

2 Major branches strictly erect; tubercles 1.3-2.6 cm; st segments 10-26 cm ............................ O. ganderi
2' Major branches more open, strongly ascending; tubercles 1-1.5(2) cm; st segments 6-40 cm ....O. wolfii

Pictures of Chollas of Anza-Borrego State Park

TaxonLinks to Pictures
O. acanthocarpa var. coloradensisplant and stem (by Wayne Armstrong, from planted specimen); flower of same plant (by Charles Jones)
O. bigeloviiComparison of entire plant, spines, and tubercles to O. Xfosbergii (by Tom Chester and James Dillane); flower and stem, comparison of entire plant to O. Xfosbergii (both by Wayne Armstrong)
O. echinocarpaPictorial Key; plants (by Wayne Armstrong); flower and stem (pix on left; by Wayne Armstrong); flower and stem (by Wayne Armstrong)
O. XfosbergiiComparison of entire plant, spines, and tubercles to O. bigelovii (by Tom Chester and James Dillane); comparison of entire plant to O. bigelovii (by Wayne Armstrong)
O. ganderiPictorial Key; plants (by Wayne Armstrong); flower and stem (pix on right; by Wayne Armstrong)
O. parryiPictorial Key; plant, stem, fruit (by Wayne Armstrong); (from Brother Alfred Brousseau)
O. ramosissimaentire plant (by Wayne Armstrong)
O. wolfiiPictorial Key; plant (by Wayne Armstrong); flower (by Wayne Armstrong)

Go to:

Copyright © 2003-2007 by Tom Chester
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
Comments and feedback: Tom Chester
Last update: 4 March 2007