blue-

Griffiths, Proceedings of the Biological Society of Washington 29(3): 13–14, 1916

Isotype; Herbarium; Herbarium; Herbarium

What is Opuntia caesia?

Opuntia caesia is a prickly pear cactus that is larger than O. phaeacantha. It may reach 2 m across and be about 60-70 cm tall with erect branches that rise from spreading, sprawling branches.

Details

Cladodes on this Opuntia are typically 10-12 cm wide by 9-12 cm long, though they are variable. The pads may narrow to a semi-stipitate base. New growth is glaucous and blue-green. There are 2-4 spines the first year that are often dark (except for pale downward sloping spines). Longest spines can be 7-8 cm long. Old spines may be more numerous and are pale.

The style is white and the stigma is green; filaments are yellow with greenish bases. The ripe fruit is purplish-red but the pulp is lighter.

Ploidy is unknown.

Other Notes

Griffiths remarked that this Opuntia has nearly as much glaucous blue bloom as O. robusta. The blue color fades to greenish or yellow-green under drought stress or with age.

The plants are abundant around Crozier, AZ. They may be low in Crozier, but are taller in Toquerville, UT. The Opuntia shares similarity with O. camanchica and O. phaeacantha, but the blue color makes them distinctive. When O. phaeacantha and O. caesia are growing together the first usually has larger pads with more areoles but is typically lower, and it definitely has less woody growth.

The original plants were described from northern Arizona.

Opuntia caesia

Opuntia caesia, near Cane beds, AZ

Opuntia caesia, near Crozier, AZ

Opuntia caesia, near St. George, UT

Opuntia tardospina

Griffiths, Annual Report of the Missouri Botanical Garden 22: 34, 1911

Herbarium; Herbarium; Herbarium; Herbarium; Photograph (top photo); Photograph; Painting

Original Description

What is Opuntia tardospina?

Opuntia tardospina is a large prickly pear cactus first reported from the Lampasas, Texas region. Griffiths reported that this Opuntia was an unusual cactus for several reasons, not the least of which were the prominent areoles.

Details

Cladodes are green or bluish-green and up to 24 by 30 cm, subcircular to obovate. Though spines are mostly absent, some yellow ones do occur that recurve or slope downwards. Under garden conditions, spines may be frequent. The glochids are numerous and prominent, up to 12 to 15 mm-long, sometimes even on pads of the current year. Areoles are prominent, up to 1 cm across in old growth and raised by 2 to 4 mm. Finally, the prominent glochids can cover old stems as in the case of O. chlorotica santa-rita.

Flowers are yellow and fruit is broadly obovate to pyriform, with areoles about 15 mm apart.

Ploidy is unknown.

Other Notes

O. tardospina differs from O. aciculata in several ways. The pads are bluer and thicker, and the trunks have glochids. The plants in these photos have curved leaves on the ovaries, which is a feature of O. cacanapa.

O. tardospina is essentially never reported. Likely this is due to the tendency to interpret any large Texas Opuntia as O. lindheimeri.

Opuntia tardospina, near Gatesville, TX, Hayes Jackson

Opuntia chlorotica gosseliniana

(Weber) Ferguson, Cactus and Succulent Journal (U.S.) 60: 159, 1988

Isotype; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium

Original Description

What is Opuntia chlorotica gosseliniana?

O. chlorotica gosseliniana is one of three varieties along with vars chlorotica and santa-rita within the O. chlorotica complex as described by Ferguson (1988). The three types blend into each other over their range where they overlap.

Details

These prickly pear cacti may reach 1 m tall (usually shorter), and are almost always tinted with pink or purple or bluish purple. Like O. chlorotica chlorotica, O. chlorotica gosseliniana has needle-like spines on older trunks and branches. Unlike O. chlorotica chlorotica, O. chlorotica gosseliniana can form multiple ascending branches. This Opuntia variety may have spines in most areoles, only in upper areoles, or in none at all. The slender spines vary from relatively short and stiff to long and flexible, up to 10 cm. Additionally, the spine color varies from cream to bright yellow and through shades of orange- and reddish-brown to nearly black.

Flowers are generally yellow from bluntly pointed buds. The stigma lobes are generally pale. Flowers are 5-7.5 cm across. Fruit is elliptical to cylindrical. This variety has smaller and relatively more slender fruit than vars chlorotica and santa-rita.

O. chlorotica gosseliniana is diploid.

Other Notes

This prickly pear is native to Mexico, and it barely reaches into the United States in far southern Arizona on land of the Tohono O’odham Nation. Thus, is is not commonly encountered. The garden plant often sold as O. santa-rita ‘Tubac’ may actually be a horticultural selection of O. chloritica gosselliniana.

Opuntia chlorotica gosseliniana 'Tubac'

Opuntia chlorotica gosseliniana 'Tubac', garden plant

Opuntia chlorotica gosseliniana, Boyce Thompson Arboretum, Superior, AZ

Opuntia chlorotica gosseliniana, cow's tongue, form, Wallace Botanical Gardens, Scottsdale, AZ

Opuntia chlorotica gosseliniana, Sue Carnahan

Opuntia chlorotica gosseliniana, TR. Van Devender

Opuntia chlorotica gosseliniana, Wallace Botanical Gardens, Scottsdale, AZ

Opuntia chlorotica santa-rita

Griffiths & Hare, New Mexico Agricultural Experiment Station Bulletin 60: 64, 1906

Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium

Original Description

What is Opuntia chlorotica santa-rita?

Opuntia chlorotica santa-rita is one of three varieties of the prickly pear cactus, Opuntia chlorotica. The varieties are santa-rita, gosseliniana, and chlorotica (Ferguson 1988). Santa-rita is the most handsome. The three varieties blend into each other over their range where they overlap.

Details

O. chlorotica santa-rita is an upright, open-branching cactus to 1.5 m with a distinct trunk (sometimes two trunks) up to 15 cm across. The cladodes are suborbicular, orbicular, or rarely obovate or even pointed. Cladodes are about 12 to 18 cm across with a bluish or purplish cast. Some individuals are strongly colored. Spines are absent in this Opuntia, or there may be 1(3) per in a few areoles at the tips of the cladodes. If spines are present they are yellow to reddish-brown or sometimes darker, and 2-3 cm long.

Britton and Rose described the flowers of this Opuntia as very handsome, deep yellow, and 6 to 9 cm across. The filaments and style are white, and the stigma is white or yellow. The fruit is oval and depressed at the apex; it is purple outwardly and greenish within and pleasant to taste.

O. chlorotica santa-rita is diploid.

Other Details

Britton and Rose reported that the type locality of this Opuntia is the Celero Mts [Salero Mt?] of AZ. It was also described from the Santa Rita Mountains. Britton and Rose also reported that “All gradations of spine characters may be found between this and the typical, very spiny Opuntia chlorotica.”

O. chlorotica santa-rita is a sumptuous and large garden plant. Its coloration alone makes it valuable, and the large, colorful flowers are a bonus. Cold-hardiness seems likely to be moderate (USDA climate zone 6?).

Desert Botanical Garden, Phoenix, AZ

Opuntia chlorotica santa-rita flowers, Michael McNulty

Opuntia chlorotica chloritica blend with var santa-rita

Opuntia chlorotica santa-rita

Opuntia chlorotica santa-rita flowers, Michael McNulty

Opuntia chlorotica santa-rita, Alan Schmierer

Opuntia chlorotica santa-rita, D Griffiths, ca. 1910

Opuntia chlorotica santa-rita, exceptional close-up of new cladode, Michael Newberry

Opuntia chlorotica santa-rita, flower, garden plant

Opuntia chlorotica santa-rita, fruit

Opuntia chlorotica santa-rita, garden plant

Opuntia chlorotica santa-rita, garden plant, Nancy Hussey

Opuntia chlorotica santa-rita, in habitat

Opuntia chlorotica santa-rita, Jan Emming

Opuntia chlorotica santa-rita, Quinn Dombrowski

Opuntia chlorotica santa-rita, Ryan Soma

Opuntia chlorotica santa-rita, with C. fulgida, Jan Emming

Opuntia sp nova aff macrocentra

Introduction

This unidentified Opuntia was observed growing in southern New Mexico near Las Cruces, near El Paso, Texas, and in adjacent Mexico. This cactus may grow alongside O. macrocentra and is similar to O. macrocentra. But, this unidentified taxon is more upright, has a different bloom period, and is a taller prickly pear. These opuntias are gray-blue or gray-green, and the spines are decidedly pale at their tips.

Opuntia unknown, No. 1

Opuntia unknown, No. 1, near El Paso, Hayes Jackson

Opuntia unknown, No. 1, near Las Cruces, NM

Opuntia macrocentra

Engelmann, Proceedings of the American Academy of Arts and Sciences 3: 292, 1856 [1857]

Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium (as O. violaceae macrocentra); Herbarium (as O. violaceae macrocentra); Herbarium (O. macrocentra minor); Herbarium (O. macrocentra minor); Herbarium (O. macrocentra minor)

Original Description

What is Opuntia macrocentra?

Opuntia macrocentra is a much-grown and much-enjoyed prickly pear cactus found in western gardens. It is related to O. azurea. The flowers are attractive and the pads are often bluish or purplish.

Details

From Powell and Weedin:

O. macrocentra plants are spreading to upright plants, 30-60 cm tall or taller. Cladodes are obovate to orbicular, 10-20 × 10-20 cm, or the pads are slightly wider than long. Spines may be produced on the upper one-fourth of the pad or only in the areoles of the upper edge. Occasionally, plants may be essentially spineless. The largest spines are often directed upwards. Spines are black to reddish-brown and 5-10 cm long.

Flowers have sharply defined, bright red centers that may be star-shaped. They are 6-8 cm long and 5.5-8 cm wide. The filaments are about 1.5 cm, pale green proximally and cream-colored distally. Anthers are yellow. The style is cream-colored and 1.7-2 cm long. The stigma lobes are cream-colored or pale green. The reddish fruit is oboviod, ovoid, or ellipsoid, 3-4.3 cm long, 1.5-3 cm in diameter, and deeply concave. The rind is purple and the juice and pulp are pale-purple to clear. Seeds are flattened, tan, 3.4-4.5 mm in diameter, 1.5-1.9 mm thick with a broad notch on one side and prominent raphae.

O. macrocentra is tetraploid

O. macrocentra minor has been described by Powell and Weedin, and it is diploid.

Other Notes

O. macrocentra has been confused with O. chlorotica santa-rita and O. azurea, but the three cacti are distinct. It is unfortunate that O. macrocentra was sometimes mislabeled as a prickly pear variety of O. violaceae because O. violaceae is a nonexistent species.

Britton and Rose reported that specimens with bluish pads can be especially showy.

O. macrocentra is an excellent garden plant in many climates. Its striking color and beautiful flowers are impressive. It is easy to grow in USDA climate zone 7 and warmer if the climate is not to wet. Plants can become large in gardens and without drought stress may not reach their best stress-caused color.

Opuntia macrocentra

Opuntia macrocentra, ca. 100 years ago, A. Shantz

Opuntia macrocentra, Dell City, TX

Opuntia macrocentra, garden plant

Opuntia macrocentra, Luc

Opuntia macrocentra, Post, TX, Derrill Pope

Opuntia macrocentra, Rio Grande Botanical Gardens, Albuquerque, NM

Opuntia macrocentra, Rodeo, NM

Opuntia confusa

Griffiths, Proceedings of the Biological Society of Washington 27(6): 28, 1914

Holotype; Isotype; Isotype; Isotype; Isotype; Isotype; Herbarium; Herbarium

See O. dulcis

Original Description

What is Opuntia confusa?

Opuntia confusa is an interesting prickly pear because some cladodes have spination similar to that of O. engelmannii, whereas other cladodes have spination similar to that of O. dulcis.

Details

In some of the obovate to subcircular pads the spines are longer than on other pads. These longer spines are heavy, angular, and spreading as in O. engelmannii. Three or more major spines may be present. In contrast, spines on other pads are slender, one porrect and one deflexed (O. dulcis like). Thus, there are two different types of spination in O. confusa that occur on different plants or even on different pads of the same plant.

The yellow flowers are 5-8 cm in diameter and darken to red or dark orange with age. Filaments are yellow and anthers are yellow. The style is pale and the stigma is green. Fruit is short-pyriform to subglobose and red. The fruit has a noticeable bloom that is lost at complete ripening at which time the fruit is dull red. Fruit spines may be reddish-brown.

Ploidy is unknown.

Other Details

O. confusa resembles O. dulcis in overall aspect and grows alongside it in some locations. However, the two generally do not produce hybrids. The two prickly pears are similar in growth form and habit. However, when they are growing together it can be seen that O. confusa is always smaller, rarely reaching 40 cm tall, and O. confusa pads average smaller as well.

O. confusa typically has large areoles with irregularly sized glochids that are scattered throughout areoles as in O. engelmannii. In contrast, O. dulcis generally has a tuft of glochids at the apex of an areole. O. confusa is a bluer plant than O. dulcis. Older (oldest) spines are darker on O. confusa than those of O. dulcis. The oldest spines of O. dulcis (on the oldest cladodes) may be black, especially in the western part of its range. See a table that compares O. confusa with O. dulcis.

O. confusa is medium-sized and an attractive garden plant because the flowers darken to red or near-red. Some forms may be hard to USDA climate zone 7 or 8.

Opuntia confusa

Opuntia confusa with fruit, AZ

Opuntia confusa, Aguirre Springs Campground, NM

Opuntia confusa, Aguirre Springs, NM

Opuntia confusa, Alamogordo, NM

Opuntia confusa, AZ

Opuntia confusa, Catalina Rd, Tucson, AZ

Opuntia confusa, Desert Botanical Garden, Phoenix, AZ

Opuntia confusa, garden plant

Opuntia confusa, garden plant, AZ

Opuntia confusa, southeastern, Tucson, AZ

Opuntia confusa, Tohono Chul Park, Tucson, AZ

Opuntia confusa, Tonono Chul, Tucson, AZ

Opuntia confusa, Tortugas Mts clone, Rio Grande Botanic Garden, Albuquerque, NM

Opuntia confusa, Tucson Mt Park, AZ Jessie Byrd

Opuntia confusa, Tucson, AZ

Opuntia confusa, Tucson, AZ, Ken Bosma

Opuntia confusa, winter color

Opuntia confusa, winter, Rio Grande Botanic Garden, Albuquerque, NM

Opuntia cacanapa (incl O. ellisiana)

Griffiths & Hare, New Mexico Agricultural Experiment Station Bulletin (New Mexico College of Agriculture and Mechanic Arts) 60: 47, 1906

Isotype; Neotype; Holotype (O. cacanapa ‘Ellisiana’); Isotype (O. cacanapa ‘Ellisiana’); Herbarium (O. cacanapa ‘Ellisiana’)

O. alta is another tree-type Opuntia

Original Description

What is Opuntia cacanapa?

Opuntia cacanapa is a large prickly pear cactus that occurs in Brewster County, TX and southeast to the Gulf Coast as well as in adjacent Mexico. It also occurs inland on the South Texas Plains where it is sympatric with other Opuntia species.

Details

O. cacanapa can reach 2-2.5 m tall. The largest branches/trunk may be 16 cm in diameter. O. cacanapa forms a large, open, branching prickly pear with blue-green and glaucous cladodes; it may grow into a tree shape or form a large shrub. The cladodes are up to 20 cm in longest diameter and are suborbicular, oval, or obovate. The 3-5 cm long spines of this Opuntia are yellow and sometimes brown or reddish-brown at the base. Spines may curve out from the areoles. Some plants may lack spines in most areoles. Leaves are strongly recurved.

The stigma of the yellow flowers is pale, yellowish-green, or pale green.

O. cacanapa is diploid.

Other Notes

Lack of spines is a feature of some Opuntia species and is not unknown. However, lack of glochids is a very unusual condition in any prickly pear.

O. alta, another arborescent Texas prickly pear, has recurved leaves, but they don’t curl back as strongly.

O. cacanapa ‘Ellisiana’ is a garden variant of O. cacanapa that has no spines at all and essentially no glochids. O. cacanapa ‘Ellisiana’ may seem different from the parent Opuntia. However, O. cacanapa and O. cacanapa ‘Ellisiana’ share key features that demonstrate their relatedness: 1) strongly recurved leaves on cladodes and flowers, 2) pale stigmas with white styles, 3) white filaments with yellow anthers, 4) general shape and size of the fruits, 5) obovate or subcircular cladodes, 6) identical bloom periods, and 7) arborescent growth or formation of large shrubs.

O. cacanapa ‘Ellisiana’ is hardy in USDA climate zone 8 and perhaps parts of zone 7. Without spines or glochids, it is a wonderful garden plant. It is not fast-growing and can be kept small by pruning. However, it needs some size to bloom.

Opuntia cacanapa

Opuntia cacanapa 'Ellisiana'

Opuntia cacanapa 'Ellisiana', Austin, TX

Opuntia cacanapa with very few spines, Megan E Hansen

Opuntia cacanapa, El Indio, TX

Opuntia cacanapa, Los Imagines, TX

Opuntia cacanapa, near Uvalde, TX, Hayes Jackson

Opuntia cacanapa, Rio Grande CIty, TX

Opuntia cacanapa, very cold weather

Opuntia cacanapa, very few spines, El Indio, TX

Opuntia cacanapa, Zapata, TX

Opuntia basilaris

Engelmann & Bigelow, Proceedings of the American Academy of Arts and Sciences 3: 298, 1856

Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Holotype (O. basilaris brachyclada); Herbarium (O. basilaris brachyclada); Herbarium (O. basilaris brachyclada); Herbarium (O. basilaris brachyclada); Herbarium (O. basilaris longiareolata); Herbarium (O. basilaris longiareolata) Herbarium (O. basilaris longiareolata); Herbarium (O. basilaris longiareolata); Isolectotype (O. basilaris ramosa); Herbaraium (O. basilaris ramosa); Herbarium (O. basilaris heilii); Herbarium (O. basilaris heilii); Herbarium (O. basilaris heilii); Isolectotype (O. basilaris woodburyi); Holotype (O. humistrata); Herbarium (O. basilaris treleasii); Holotype (O. basilaris whitneyana); Painting; Painting; Painting

Original Description

What is Opuntia basilaris?

Opuntia basilaris is a distinctive prickly pear cactus; it has the archetypical “beaver tail” look. Mature plants form dense clumps 15-30 cm tall and 30-100 cm across. The pads are blue-green or grayish-green and are often wedge-shaped or broadly obovate. Pads are (7)15-17(22) cm long.

Details

Often the cladodes of this prickly pear are fan-shaped, but they may be oval, obovate or even elongate-obovate. The pads of the major variety of this Opuntia (var basilaris) arise from a single point and form an approximate rosette. The areoles are slightly sunken. This prickly pear has blue-green or gray-green pads that are distinctive and that may have hints of purple, or they may be entirely purple under stress. Though spineless, there are numerous small glochids to be avoided.

Flowers are magenta and about 7-8 cm across, very showy. Fruit is dry. The style is white or pinkish-white, and the stigma is white. Filaments are red, anthers are yellow. The seeds are large and thick (subspheric?) and angular. They measure 6.5-9 × 6.5-7 mm.

O. basilaris basilaris is diploid, but O. basilaris treleasei is triploid.

Other Notes

We recognize five varieties of this Opuntia:

basilaris
brachyclada
longiareolata
ramosa
treleasei

Britton and Rose discuss several varieties that are not recognized here including: albiflora, coerulea, and nanna. O. basilaris basilaris is by far the most commonly encountered variety. All varieties of this prickly pear are spineless except var treleasei.

Native Americans used O. basilaris as a medicinal plant (Anderson, 2001). Perhaps there was some beneficial effect to ingesting the cactus because it contains 3,4-dimethoxyphenethylamine, a compound related to dopamine and mescaline.

O. basilaris is a favorite in gardens because of its unique shape, pad colors, and bright flowers. Some clones from higher altitudes are cold-hardy.

Opuntia basilaris

Opuntia basilaris brachyclada

Opuntia basilaris brachyclada, John Weiser

Opuntia basilaris heilii, Nancy Hussey

Opuntia basilaris hybrid, AZ

Opuntia basilaris longiareolata, Desert Botanical Garden, AZ

Opuntia basilaris longiareolata, UT

Opuntia basilaris ramosa

Opuntia basilaris treleasei

Opuntia basilaris treleasei, southern California, Michelle Cloud Hughes

Opuntia basilaris with elongated cladodes, Nancy Hussey

Opuntia basilaris, AZ

Opuntia basilaris, bud from white-flowered form, Nancy Hussey

Opuntia basilaris, Bullhead City, NV

Opuntia basilaris, flower, Red Rock Canyon National Conservation Area, NV

Opuntia basilaris, Gold Point, NV

Opuntia basilaris, Kingman, AZ

Opuntia basilaris, NV

Opuntia basilaris, Red Rock Canyon National Conservation Area, NV

Opuntia basilaris, Searchlight, NV

Opuntia basilaris, west face of Mt. Charleston, NV

Opuntia basilaris, white flower, Nancy Hussey

Opuntia basilaris, white flowers, garden plant, Nancy Hussey

Opuntia azurea

Rose, Contributions from the U.S. National Herbarium 12(7): 291, 1909

Holotype; Isotype; Isotype; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium (O. azurea diplopurpurea); Holotype; (O. azurea diplopurpurea); Holotype (O. azurea discolor); Herbarium (O. azurea discolor); Herbarium (O. azurea parva); Herbarium (O. azurea parva); Herbarium (O. azurea parva); Herbarium (O. azurea parva); Painting (possible O. azurea)

See O. chisosensis

See O. macrocentra

What is Opuntia azurea?

Opuntia azurea is an attractive prickly pear cactus from the Big Bend Region of Texas that is related to O. macrocentra.

Details

A full technical description of this Opuntia and its proposed varieties begins on page 130 of The Cacti of the Trans-Pecos and Adjacent Areas (Powell and Weedin, 2004).

Powell and Weedin described five varieties of O. azurea.

aureispina
azurea
discolor
diplopurpurea
parva

We include a sixth possible variety of this prickly pear that is undescribed. We provisionally refer to it as O. azurea casteretti. Perhaps O. azurea casteretii it is only a white-spined version of O. azurea diplopurpurea. Powell and Weedin considered these white-spined plants to be variants of O. macrocentra and nothing more.

O. azurea is tetraploid or hexaploid depending upon the report. Perhaps polidy varies with variety, but there is no evidence to support this idea.

Other Notes

This Opuntia is a wide-ranging (into Mexico) and variable species. Depending upon the variety, the plant may be purple at the cladode base or may turn entirely purple in winter. Spines may be slender or robust. Also, varieties are differentiated by height with some 1 m or taller and others less than 1 m. Additionally, cladode size may differentiate varieties.

The Flora of North America does not recognize this taxon.

O. azurea is cold-hardy and attractive in any collection.