OPUNTIA 



OPUNTIA 



2357 



wliicli ajipears a small caducous pointed If., rarely 

 spreadius and foliar; an oval or circular area, more or 

 less covered with soft wool, intermixed with barbed 

 bristles and usually a variable nmnber of s])ines, occurs 

 in the axil of each If.; fls. borne singly towanl the ujiper 

 part of the joints or sts., on the bristle-bearing part, of 

 the areole, and with spreading, showy corollas; the 

 usually many-o\ided inferior ovaries are not of foliar 

 development, and sometimes differ but slightly in 

 apjiearance from normal sts., usually bristle- and sjjine- 

 bearing: fr. dry or succulent, frequently edible; seeds 

 large, flattened, discoid and often margined. — There are 

 about 130 species and many varieties an(.l hybrids, 

 extending from Canada southward through the U. S., 

 Mex., W. Indies and Cent. Amer. to the southern jjart of 

 S. Amer. The species are confined mostly to arid and 

 semi-arid regions; however, some are found in regions 

 of hea\'7i' rainfall. They are found in greatest quantity 

 and variety of species in S. W. U. S. and N. Mex., 

 where they are often trees and form the most conspicu- 

 ous part of the flora. Opuntia is a genus of great varia- 

 tion in habit and appearance, and, from the frequency 

 of natural hybrids and ill-defined specific lines, one of 

 the most difficult genera of flowering plants to present 

 satisfactorily in systematic order. Some of the largest 

 cacti are opun1 ias, while nearly all that are of economic 

 value belong to this genus. 



Although the opuntias are less attractive as pot-plants 

 and, on account of their barbed spines and bristles, 

 more difficult to handle than most other cacti, they 

 are coming into favor on account of their unique 

 appearance, rapidity of growth antl attractive flowers. 

 They grow laest with an abundance of heat and sunlight, 

 the character of the soil being a secondary considera^ 

 tion. Like all other cacti, they require perfect drainage. 

 They are readily grown from cuttings, and also from 

 seed under proper management. 



Economically considered, the opuntias are by far 

 the most important of the cacti. Although originally 

 confined to the New World, the more important species 

 are now in cultivation or have escaped from cultiva^ 

 tion and become wild in every arid and serai-arid 

 region of the globe where the temperature permits their 

 being grown. Wherever grown, their tendency is to 

 escape from cultivation and become persistent and 

 troublesome weeds. In this respect they are much more 

 to be dreaded in foreign countries than in America, the 

 place of their nativity. 



As ornamental plants, opunti;is are unusual rather 

 than pleasing. From their stiff, formal aspect they do 

 not harmonize, as a rule, with other plants, and on 

 account of their spines and bristles they are difficult 

 to hantlle and are considered by most gardeners as a 

 nuisance in decorative planting. It is as hedges and as 

 groups of mixed species that they are most effective. 

 Most species grow rapidly and bloom profusely. The 

 flowers, as a rule, are large and showy and of various 

 colors, although yellow predominates. They wither 

 soon after opening and remain at their best only for a 

 few days. The spines and bristles which u.sually cover 

 the base of the flowers render them of no value as cut- 

 flowers. With many species, such as O. leptocaulis, 0. 

 tetracantha, and some forms of 0. Tuna, the bright- 

 colored fruits, which remain on the plants for a long 

 time after ripening, render them more attractive in 

 fruit than in flower. Crested or fasciate forms (Fig. 

 2596) are common. 



Although extensively cultivated for their fruit in 

 many countries, where the}' furnish an important 

 article of tliet for four to five months each year, they do 

 not as yet take a pomological rank with the horticul- 

 turist, although they are much more widely used and of 

 far more economic importance than many plants which 

 have an established place in [loinolngical literature. 

 From the fact that opuntias flourish best in regions 

 where experimental horticulture receives little or no 



,5»:.'V 



attention, the development of desirable economic 

 varieties has not been what might be expected of plants 

 which respond so readily to cultivation and selection, 

 and which may be hybridized with so little difficulty. 

 Botanically considered, the fruit is a kind of berry, 

 varying from dry to fleshy and succulent. Morpho- 

 logically, it is a modified stem with the true seed-capsule 

 sunken into its apex; hence it bears leaves and spines, 

 and usually, under suitable conditions, and frequently 

 in the natural state when it becomes detached, will bud 

 and grow like a normal stem-cutting. 



Opuntias were cultivated by the aborigines of 

 America at the time of its discovery, and were early 

 taken by the Spanish explorers to Spain and Spanish 

 colonies in other parts of the world. After becoming 

 established in the Canaries, Azores, and Madeira 

 islands, it was not long before their culture extended to 

 Portugal, Spain, and the whole littoral region of the 

 Mediterranean. From there they spread to Egypt, 

 India, and other parts of southern Asia. In compara- 

 tively later times they reached South Africa, Australia, 

 and New South Wales, where they are fast becoming a 

 serious menace to agriculture and grazing. In all the 

 regions above noted they have escaped from cultiva- 

 tion and have become pestiferous weeds. 



The want of fixed characters, the great variations 

 in most species under different soil and climatic con- 

 ditions, and the readiness with which natural hybrids 

 occur, make the identification of cultivated and intro- 

 duced species so difficult that the considerable literature 

 on this subject is extremely uncertain as to nomencla- 

 ture. The common 

 names Indian fig, bar- 

 berry fig, prickly pear, 

 and tuna, are applied 

 indiscriminately b y 

 most persons to any 

 flat - jointed opuntias, 

 but more particularly 

 to the kinds with edible 

 fruits. 



The two most widely 

 distributed and exten- 

 sively cultivated are 

 O. Ficus-indica and O. 

 Tuna. These plants 

 have often been con- 

 fused by authors. 

 Much that has been 

 written under the name 

 of one species really 

 applies to the other. 

 They are closely linked 

 together by hybrids, 

 and each has been in 

 cultivation for so long 

 a period that numer- 

 ous cultural varieties 

 have developed, partic- 

 ularly in Mexico and Sicily. It is possible that the 

 many cultivated forms of both species originated from 

 the same source. 



Although the Mexicans and Indians eat the fruit of 

 more than a score of indigenous species, the two named 

 above, with their many cultivated forms, are by far the 

 most desirable and palatable. O. Ficus-indica is prefer- 

 able in most respects to O. Tuna on account of its fewer 

 and smaller spines and usually larger fruit. The latter, 

 however, makes a more formidable hedge, and is more 

 frequently planted in the United States. Hedges of 

 this plant are to be seen at many of the old Spanish 

 missions in Arizona and California, where they were 

 probably first introduced into the United States. O. 

 Ficus-indica is frequently grown by the Mexican popu- 

 lation of New Mexico, Arizona, and California. In 

 southern Floriila it has escaped from ciiltivation and 



2596. Opuntia ramosissima. To 

 illustrate fasciation, which is of 

 frequent occurrence in nearly all 

 species of cacti. 



