ICOSANDRIA. 155 



is not large, but is exceedingly important to man, as contain- 

 ing many oi' the most delicious, and widely diffused fruits of 

 (he earth. Among these are the Apple, Pear, Cherry, Prune, 

 and Plum. It also contains the Rose tribe, which for variety, 

 beauty, and fragrance, is the prince of flowers. The genera 

 of this class are most of them extremely natural, there being 

 a likeness in appearance, habits, or qualities, in most of the 

 species belonging to each. These have likewise been 

 studied with unusual attention, owing to their domestic im- 

 portance, and the great length of time most of them have been 

 cultivated. This latter circumstance has, however, made 

 some of the species exceedingly perplexing in their botanical 

 relations, owing to the great changes they have undergone 

 by cultivation. The pupil will, therefore, much more fre- 

 quently find himself at a loss concerning the botanical char- 

 acters of plants which he has known from his infancy, 

 than with respect to many which he has seen for the first time. 

 The class contains three orders. 



ORDER MONOGYNIA. Stamens many, perigynous. Style 1. 



GENUS Cactus. This name was used by Theophrastus, to 

 signify an unknown, spiny plajit, which was edible. The 

 Cactus tribe presents a large number of grotesque, or curious 

 looking succulent plants, generally without leaves and having- 

 thick, jointed stems. For the most part they are armed with 

 spines, with which bristles are often intermixed. This tribe 

 is called Indian Fig, arid one or two species are known under 

 the name of Prickly Pear. A majority of the genus are na- 

 tives of South America, but are now common in the West 

 Indies. Most of them are green-house plants in our climate, 

 though the Prickly Pear, (Cactus opuntia,) is common along 

 the Hudson river, and is found in every part of the United 

 States, south of New York. See Torrey's Flora. The cele- 

 brated flower called Night blooming Cereus, ( Cactus grandi- 

 florus,) belongs to this genus. This has a creeping, jointed, 

 five angled stem, which sometimes grows several yards in 

 length in our hot houses. The flowers proceed from the sides 

 of the stem, and are exceedingly large, splendid and sweet 

 scented, but of short duration. These flov ,rs begin to open at 



What are among the most important plants belonging to this class ? 

 Why are the botanical relations of domestic plants, more difficult than 

 those of wild ones ? What is the botanical name of the night blooming 

 cereus, and to what genus does it belong? 



