large-

These are Opuntias that form large shrubs or small trees at maturity.

Opuntia ochrocentra

Kunkel ex Britton and Rose, The Cactaceae; descriptions and illustrations of plants of the cactus family 4: 262–263. 1923

Lectotype; Herbarium; Herbarium

Original Description

What is Opuntia ochrocentra?

Opuntia ochrocentra is a small- to medium-sized prickly pear cactus from the Florida Keys. (All pictures provided by Danny Green.)

Details

The pads of O. ochrocentra are elliptic to oval or even obovate, 10-30 cm long. There are 5-6 yellow spines in many of the prominent areoles. Spines are reflexed. 

Flowers are yellow with few petals, and the obovoid fruit is red, about 2 cm long. 

Ploidy is unknown. 

Other Notes

The type specimen was collected on the southeastern end of Big Pine, Key, Florida. The original description indicates that the taxon is related to O. dillenii but that it differs in the shape of the joints and in the possession of strongly reflexed, scarcely flattened spines. 

Opuntia keyensis

Opuntia keyensis
Opuntia keyensis

Britton & Small, Journal of the New York Botanical Garden 20: 31, 1919

Herbarium; Herbarium; Black and White Photograph

Original Description

What is Opuntia keyensis?

Opuntia keyensis is native Florida prickly pear cactus found in the Keys and Cape Sable. 

Details

O. keyensis is a large, erect, multi-branched cactus that forms a shrub or small tree growing to 3 m tall, but shorter individuals are common. The bright-green cladodes are oval, obovate, or even spatulate–thick and 10-30 cm long. The spines are short and hidden within the 1 cm long glochids, but this prickly pear definitely has spines. The spines are stout, pink when new and salmon-colored at maturity. There are 4-13 spines per areole.

The flowers are solitary or several per cladode and pale pink or salmon-colored. The buds are short-pointed. The corolla is cup-like or short-campanulate, 3-3.5 cm wide, with relatively few tepals. The fruit is obovoid and 4-6 cm long, with a strong narrowing at the base. Seeds are numerous. 

Ploidy is unknown. 

Other Notes

O. keyensis is found on hammocks in the Florida Keys and in the Cape Sable region. It is found only near the ocean. It is a suitable garden plant for large gardens in frost-free areas. 

Opuntia tardospina

Opuntia tardospina
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 discata

Opuntia discata
Opuntia discata

Griffiths, Annual Report of the Missouri Botanical Garden 19: 266, 1908

Isotype; Isotype; Herbarium; Herbarium

O. discata has some similarities with O. engelmannii

Original Description

What is Opuntia discata?

Opuntia discata is a handsome, large prickly pear cactus. It is ascending and compact to 1-1.4 m tall and perhaps as wide. The distinctive, white spines provide beauty and character. 

Details

O. discata cladodes are about up to 25 cm wide and often circular or broadly obovate, sometimes elliptical. Cladodes are a handsome dark green when young but turn to waxy gray or blue-gray at maturity. Spines are chalky white or dirty white and reddish-brown or darker towards the very base. A very pale, pink tinge may permeate. Overall however, the spines appear bone-white against the pads. Spines may be up to 2.5 cm long but more commonly 1-1.5 cm and are present in 2/3 or most areoles. There are 3-5(7) in uppermost areoles, whereas lower areoles may have a single spine. Spines are erect, but few are precisely perpendicular to the pad. Mostly they have a gentle curve outwards or just lean outwards. They seldom curve parallel with (or back towards) the cladode. 

The lemon-yellow flowers may darken to orange at the base, or they may change to orange over the day of anthesis. Filaments are greenish-white, the style is white, and the stigma is dark green. Fruit is obovate or roundish and seldom narrows to a neck. Fruits are a deep, dark-red, about 6-7 cm in length. 

O. discata is hexaploid.

Other Notes

O. discata is sometimes confused with O. engelmannii because the two are large, but the former is compact and the latter is is a more open prickly pear. O. engelmannii often has has a more upright stance than O. discata. Seen side-by-side they are distinct and they don’t interbreed. See a table comparing O. engelmannii with O. discata. 

Britton and Rose reported that this Opuntia is found on “the foothills and mesas of southern Arizona and northern Sonora, Mexico.” There is some uncertainty about the name, discata. Some interpretations of the literature suggest the species could be called O. microcarpa. Our review suggests that O. discata has precedence as a name. 

O. discata is a beautiful plant in larger gardens. It might be cold hard to about zero F. 

Opuntia canada

Opuntia canada
Opuntia canada

Griffiths, Annual report Missouri Botanical Garden 20: 90, 1909

Holotype; Topotype; Herbarium (as O. engelmannii); Painting

Original Description

What is Opuntia canada?

Opuntia canada is a large, erect, ascending cactus that grows in far southern Arizona. It is a compact-appearing prickly pear. 

Details

O. canada grows in thickets or singly. This Opuntia may reach 1 m in height, but taller plants are known. It has ovate or obovate cladodes approximately 16 by 22 cm. But cladodes are variable in size, especially when young. Areoles are brown when young but turn black. However, they often retain a brown center because new wool continually develops in the center of the areole. Spines may not be present till cladodes are two years-old, but then they may be conspicuous. Spines are variable but are commonly yellow when young and bleaching to white. There are (1)2-3(5) spines per areoles, about 12-15 mm in length. They increase in number and length on older growth. Overall, there are fewer spines per areole than in O. engelmannii. 

The flowers are yellow but may be tinged with reddish or orange on the bases of the inner tepals. The style is white or white tinged with red. The stigma is bright green. Fruit may be light red or mottled yellow and red. Seeds are flat but thick and angular, 3-3.5 mm in diameter with a prominently notched hilum. 

Ploidy is unknown. 

Other Notes

O. canada shares some similarities with spiny forms of O. laevis; however, the two species are consistently different. For instance, O. laevis grows on canyon walls or the rubble at the base, whereas O. canada grows in deeper soils, often on canyon floors. O. laevis has longer and more narrow cladodes. Also, O. laevis has hairy seedlings and longer fruits. 

Opuntia laevis

Opuntia laevis
Opuntia laevis

Coulter, Contributions from the U. S. National Herbarium 3: 419, 1896

Holotype; Isotype; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Painting (Britton and Rose, v1 1919, plate XXVIII)

 Original Description

What is Opuntia laevis?

Opuntia laevis is a sometimes spineless prickly pear cactus that grows in various locations in southern AZ but particularly on canyon walls or in the rubble below rather than canyon floors.

Details

O. laevis plants are naturally nearly spineless, or they may have a few short spines at the tips of cladodes or along the surface, but just a few. Cladodes on this prickly pear may be large, up to 10-12 cm wide and 30 cm long. They are often narrow proximally or may be elliptical, long-obovate, or sometimes obovate. Areoles are small, 3-4 mm long. Leaves are modestly recurved. 

Flowers are yellow and tinged with red, about 6 cm broad. Stigmas are slender. The fruit is pyriform, 5-6(8) cm long and deeply umbilicate. The seeds are irregular and about 5 mm in diameter with a thick, undulate margin.

O. laevis may be diploid.

Other Notes 

At one time,  O. laevis was considered a variety of O. phaeacantha. More recently, a proposal has been made to place O. laevis as a variety of O. engelmannii. However, we continue to accept O. laevis as a stand-alone species.  Because it is nearly spineless, it is sometimes misidentified in gardens as Burbank’s spineless cactus or even O. cacanapa ‘Ellisiana’.

Opuntia gomei

Opuntia gomei
Opuntia gomei

Griffiths, Annual Report of the Missouri Botanical Garden 21: 167, 1910

Holotype; Holotype (O. laxiflora); Isotype; Isotype (O. laxiflora); Herbarium (submitted as O. lindheimeri); Herbarium (O. cyanella); Herbarium (O. gilvoalba); Photograph (O. gilvoalba); Herbarium; O. gomei (painting); O. gomei (painting, O. laxiflora)

Original Description

What is Opuntia gomei?

Opuntia gomei is a common prickly pear near the Rio Grande River delta, but it may occur inland somewhat on the South Texas Plains. Britton and Rose conflated it with O. lindheimeri, but it is a distinct stand-alone species and intermediates are not found. 

Details

O. gomei may form large shrubs 1-1.5 m tall and up to 3 m across. Major branches of this opuntia often rest upon the ground and other branches arise from them. Old, large cacti often contain dead material in the centers. Large cladodes may be roundish and 40 to 60 cm (or more) in diameter. The largish pads are often scalloped. The yellow spines are erect and divergent. The spines are 2-4(5) cm long, and there are often 2-4(5) spines per areole, which are stout, straight, and not curved. Glochids are abundant and prominent in this opuntia, up to 1 cm. The glochids may fill the entire areole as is the case with O. lindheimeri.  

The flowers are yellow, but red flowers have been reported. The stigma is large and bright deep-green. The fruits are reddish purple.

Ploidy is unknown. 

Other Notes

O. gomei appears to by synonymous with O. gilvoalba, O. laxiflora, and O. cyanella. 

Young plants are handsome and the yellow spines make a focal point for any garden. However, O. gomei is a large plant and is not suitable for smaller gardens. It may be hardy to 10F. 

Because it is found in the Rio Grande River delta on slight elevations, it is proposed the species may be able to tolerate salts and occasional flooding. 

Opuntia oricola

Opuntia oricola
Opuntia oricola

Philbrick, Cactus and Succulent Journal (U.S.) 36(6): 163, 1964

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

Original Description

What is Opuntia oricola?

Opuntia oricola is a medium-sized, easy-to-recognize prickly pear cactus found in coastal California. 

Details

O. oriciola pads are 15 to 26 cm long and 12 to 19 cm wide, elliptic to circular. Spines are yellow, translucent, and narrow. Centrals may be twice as long as radials, and spines are present in essentially all areoles.

The flower is yellow but may have tinges of red or orange on outer tepals. The style is bright red with a bulbous base, the stigma lobes are yellow or golden. The fruit of this Opuntia is spherical or egg shaped with a deep umbilicus. Fruit is medium-red with many areoles that have copious, brown glochids 

O. oricola is triploid.

Other Notes

O. oricola is the one cactus that was called O. littoralis the most consistently (but incorrectly) until Philbrick fixed the problem by naming it O. oricola. Everything got confused when, at the same time, L Benson expanded the concept of O. littoralis to include other taxa (including O. oricola). However, O. oricola is nothing like O. littoralis.

This prickly pear cactus grows from Santa Barbara, California to Ensenada, Mexico, including the Channel Islands. It typically occurs with coastal sage vegetation in disturbed habitats on south-facing slopes at 150 m or less.

Opuntia occidentalis

Opuntia occidentalis
Opuntia occidentalis

Engelmann & J. M. Bigelow, Proceedings of the American Academy of Arts and Sciences 3: 291, 1856

Syntype; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium

Original Description

What is Opuntia occidentalis?

Opuntia occidentalis is a prickly pear cactus that occurs in southern California. Britton and Rose reported that the type locality is the “western slopes of the California Mountains,” between San Diego and Los Angeles. The cactus also occurs on the islands off the California coast.

Details

O. occidentalis is a large prickly pear (up to 1.2 m tall) with similarities to O. engelmannii.  It may form large single-species thickets. Cladodes are typically obovate, blue-green, 20 cm wide and up to 30 cm long, but they may be larger or smaller. Dark red-brown spines are typical, but they may be pale at the tips.

Flowers are yellow but may have reddish tints. Fruit is reddish-purple, occasionally green, and sweet. Seeds are larger than in the similar O. engelmannii.

O. occidentalis is hexaploid.

Opuntia semispinosa

Opuntia semispinosa
Opuntia semispinosa

Griffiths, Bulletin of the Torrey Botanical Club 43(2): 89, 1916

Holotype

Original Citation

What is Opuntia semispinosa?

Opuntia semispinosa is a coastal prickly pear cactus from southern California and Mexico that has been variously lumped into O. occidentalis, O. littoralis, or even other opuntias of coastal California. We accept it as a stand-alone species.

Details

Plants my reach 1 or 1.4 m tall and 1 or 2 m wide. Originally the plants grew in great thickets, but land use eroded this habit and this opuntia now often grows singly or as a few individuals. This prickly pear can present as an untidy collection of branches and irregular cladodes because the branches are angular. Some plants are compact whereas others spread. Segments of this Opuntia may be oval or obovate and or even pointed at both ends (almost rhomboid). Spines are white, but larger centrals may darken to brown at the base. Larger spines are often angular and twisted. Interestingly, areoles can sometimes be wider than long, 5 mm wide and 6-8 mm wide.

Flowers are yellow but may have a tinge of orange. Filaments are yellowish or pale green and the style is red and large, up to 8 to 10 mm in diameter. The stigma is pale green. The outer sepals are often recurved in bud. The fruit is 35 × 50 mm and obovate with a flat umbilicus. The fruits of this prickly pear are spiny. 

Ploidy is unknown. 

Other Notes

O. semispinosa was initially collected at Santa Barbara, CA, San Pedro, CA, and near Tija Juana, Mexico. 

At one time there was much interest in the plant as a possible source of spineless Opuntia germplasm because some pads are spineless over part or all of the of the pad (hence “semi” spinosa), but this hope was not realized. O. semispinosa is not a prickly pear generally found in gardens due to its  large size.