390 



DOMESTIC BOTANY. 



culencj, and in age becomes hard- wooded light timber; it is 

 used in Chili for house building and other purposes. 



C. giganteiis. A native of New Mexico, growing in dry 

 arid places. It has a cylindrical fluted stem, consisting of 

 about twenty ridges, and rises like a column to the height of 

 50 or 60 feet, having the appearance of posts ; the older ones 

 branch at the top, the branches being erect, and when seen 

 at a distance give the idea of a toasting-fork. The fruit is 

 analogous to the Indian fig. 



C. senilis. Also a native of Mexico, in the district of 

 Real del Monte, Avhere it grows in a hot valley, called Terra 

 Calientes. It has a tall cylindrical stem, consisting of many 

 ridges, growing to the height of 20 or 30 feet, with a dia- 

 meter of 9 to 10 inches. In 1846 about 100 plants were 

 received at Kew, varying in size from 1 to 3 feet, while three 

 specimens were from 8 to 12 feet high. In the greater number 

 of them the roots were on one side at a right angle with the 

 stem, clearly showing that they were grown in crevices of 

 rocks. The whole aspect of the plant is of a grey colour, 

 the top part being furnished with long white hairs and 

 spines, which has led to its being called the Old Man Cactus. 

 The stem of this plant contains a large quantity of oxalate 

 of lime in small sand-like grains, which renders it very 

 heavy and brittle. 



3. Epiphyllum. 

 Stems hrancliing, composed of short truncate joints. Petals 

 of the flower unequal in size, forming an oblique bilabiate 

 floiver. 



This section is represented by E. truncatiim and E. Eus- 

 sellia, natives of Brazil, and growing on trees. They have 

 been long introduced into this country, and are much cul- 

 tivated as ornamental plants for their crimson flowers. 



4. Echinocactus (Hedgehog Cactae). 



Plants of more or less oblong, globose, conical shape, rarely 

 plain or few angled, generally composed of numerous project- 



