GEBAmALES. 



543 



are pretty, and many exotic species (mostly South African), which are 

 in common cultivation. 



Tropmolum majus, the Nasturtium, from South America, is in com- 

 mon cultivation. The edible tuberous roots of 7'. tuberosum, of Peru, 

 are used instead of potatoes in some parts of South America. 



Pelargonium is another South African genus, which has furnished 

 us with many iine greenhouse and garden flowering plants, most of 

 which are erroneously called Geraniums. 



The true Geraniums belong to the genus of that name represented in 

 this country by eight or nine wild species. 



Erodium cicutarium, the Alfilaria, of California, " is a valuable and 

 nutritious forage plant reputed to impart an excellent flavor to milk 

 and butter." (Brewer.) 



Order Zygophyll- 

 acese. — Shrubs and herbs 

 (a few trees), with oppo- 

 site compound leaves ; 

 stamens distinct ; spe- 

 cies, about 100, almost 

 confined to the tropics. 



Ouaiacum officinale, 

 the Lignum-vitse, of the 

 West Indies, is a tree 

 six to nine metres (20 to 

 30 feet) high, whose dark 

 red, almost black, heart- 

 wood is exceedingly 

 hard ; it furnishes the 

 best material for ship's 

 blocks, pulleys, etc. 



Larrea Mexicana, the 

 Creosote Bush of Arizona, is a curious diflFusely branched evergreen 

 shrub, with a very strong creosote-like odor. 



Order Xalpighiacese, — Trees and shrubs, often climbing ; natives 

 for the most part of the tropics ; species, 580, some of which are culti- 

 vated in greenhouses. 



Order Huuiiriacese. — Balsamic trees and shrubs of tropical America 

 and Africa. 



Order Linacese. — The Flax Family. Herbs, shrubs, and a few trees^ 

 with alternate or opposite simple leaves ; stamens more or less united 

 below ; species, 135, widely distributed in temperate and tropical 

 climates. 



The most important plant of the order, and one of the most impor- 

 tant in the vegetable kingdom, is the Flax, Linum usitatissimum, cul- 

 tivated from time immemorial for its fibres, called linen (the bast fibres 



A B 



Fig. 507. — A, the frnlt oflmpatiens Balfiamina. By 

 the same after dehiscence ; a, a, carpels ; gr, eeeds, 

 — After Duchartre, 



