290 THE DAISY FAMILY. 



blossomed Rhipsalis. The sepals are usually indefinite in number, 

 and gradually merge into petals, so that it appears as if the flower 

 were destitute of calyx, and the corolla gradually diminished outwards 

 and downwards into coloured bracts. They are often scattered over 

 the whole surface of the ovary, which is large and long, and resembles 

 a fleshy peduncle. The latter ripens into a succulent, many-seeded 

 firuit, which is either insipid, or refreshing and agreeable. Such is 

 the case with the celebrated fruit called the " Indian fig," occasionally 

 imported from the West Indies, and sold in the shops imder the name 

 of the " Indian pear." 



Four principal forms of these remarkable plants may be discri- 

 minated, all of them common in green-houses. When the stem is 

 flattened and two-edged, with shoots growing from the joints, they 

 are called Opuntias, or prickly pears ; when tall, pillar-like, unbranched, 

 and with many angles, they are termed torch-thistles ; when very 

 long, weak, and slender, so as to hang down in pendulous tails, they 

 are called Cereuses ; and when globular and unbranched, they are called 

 melon-thistles, or Echinocacti and Melocacti. Besides these, there are 

 the species in which leaves are developed, but the latter are unusual. 



America is the exclusive habitation of the Cactaceae in the wild 

 state, the greater portion occurring in the tropical parts. One or two 

 species have naturalized themselves in the vicinity of the Mediter- 

 ranean, but there is no reason to suppose that they are truly indigenous 

 anywhere in the eastern hemisphere. The " night-blowing cereus" is 

 remarkable for not opening its flowers till 10 p.m. ; and the Opuntia 

 cochinillifer is invaluable as the residence of the insect that furnishes 

 cochineal. 



XCI.— THE DAISY FAMILY. Composite or Asterdcea. 



The Daisy Family is the largest known to Botany, the estimate of 

 species being 9,000. It is one of the best marked and soonest recog- 

 nized, the characters lying in very small compass, and subject to little 

 variation. The mass of the family consists of herbaceous plants, 

 varying from the size of the daisy to that of the sunflower ; but abroad 

 there are many shrubby and almost tree-like species. In regard to 

 stems and leaves, they present every conceivable variety, the only 

 characters in which the latter agree throughout, being the negative 



