8(j CACTACEOUS PLANTS. 



gardens in which it ia employed being also given. In England this Opuntia 

 flowers very freely, its large yellow blooms being very attractive. O. horrida 

 well deserves its name, for it is a most formidable plant, the spineB 

 2 to 3 inches long, very strong, of a peculiar tawny colour, and in clusters of 

 Eeveu or eight each. 0. imbrioata has irregularly cylindrical branching 

 stems and tufts of white spines. 0. Kleinise, also with cylindrical stems, 

 receives its name from a slight resemblance to some of the Kleinias. O. lep- 

 tooaulia is one of the most slender-growing Opuntias, the stems often not 

 exceeding one-eighth of an inch thick. O. leucotrioha has a curious appear- 

 ance, owing to its oval flat branches being closely covered with long white 

 spines, which are deflected towards the base of the plant and almost level 

 ■with the surface. O. microdasys is a rather pretty dwarf and much-branched 

 species, which with its variety ruflda, has numerous small tufts of reddish- 

 brown hair-like spines covering the elliptical flattened branches. O. mona- 

 cantha. — This ia one of the best known of the flat-stemmed Prickly Pears, 

 as it is largely grown for sale with the miniature Cacti. It has dark green 

 stems, with scattered solitary spinea, and beara neat bright orange-coloured 

 flowers. 0. nigricans. — This is another of the largest specimens at Kew, 

 one old example there being of corresponding dimensions to 0. decumana — 

 namely, 12 feet in height, the branches 12 inches long by 6 inches broad, and 

 bearing very dark spines 2 to 3 inches long, the flowers orange-red, and the 

 fruits pear-shaped and rich crimson when ripe. This has been described as 

 Tuna major (Dillenins), as Cactus Tuna var. nigricans, as Cactus Tuna, and 

 as Cactus nigricans, and it appears to be one of the species upon which the 

 cochineal insect lives. 



PEEESKIA, Miller. 

 (TliG Gooseberry Cactus.) 



In all the preceding genera o£ the Cactus family we have been 

 reviewing a form of vegetation widely different in appearance from the 

 ordinary characters of flowering plants, particularly as regards the stem 

 Ktructure, but iu the Pereskia by a sudden transition we come to a group 

 of plants evidently connecting the family with several orders. The stems 

 have lost the bulkiness of many Cacteas, and though still fleshy in a 

 certain degree, and armed with clusters of spines, they are cylindrical 

 and more shrub-like in form, while they bear normal leaves veined like 

 the majority of exogens, and often with a distinctly developed stalk 

 (petiole). The flowers, too, are very distinct, the petals being rotate — . 

 that is, spreading like the spokes of a wheel, and in several cases they 

 bear a close resemblance to single Rosea. The flowers are produced in a 

 form of inflorescence, which is not found in any other member of the 

 family — namely, clustered or paniculate at the sides or points of the 

 branches, fkUd this alone gives the Pereskias a unique appearance, and 



