IN EXTRA-TROPICAL COUNTRIES. 215 



herb, fond of marly soil, and living in dry localities. It is thus 

 well adapted also for the limestone formation of the lower 

 Murray River. It prepares dry calcareous soil for cereal culture. 

 Stagnant underground humidity is fatal to this plant. It prospers 

 still where Red Clover and Lucerne no longer succeed. Sheep 

 cannot be turned out so well on young Sainfoin fields as cattle. 

 The hay is superior even to that of Lucerne and Clover. The 

 plant will hold out from five to seven years (Langethal). It yields 

 much honey for bees. . , 



Onosma Emodi, Bentham. ( Maharanya Emodi, A. de Candolle.) 



Nepal. The root, like that of the Canna tinctoria, produces a red 

 dye. 



Opuntia coccinellifera, Miller. 



Mexico and West India. The Cochineal Cactus. On this and 0. 

 Tuna, O. Hernandezii, and perhaps a few others, subsists the 

 Coccus, which offers the costly cochineal dye. Three gatherings 

 can be effected in the year. About 1,200 tons used to be imported 

 annually into Britain alone, and a good deal also to other countries, 

 valued at about .400 for the ton. The precious carmin pigment 

 is prepared from cochineal. Different Cochineal Opuntias occurs 

 also in Argentina. Some species of Opuntia will endure a tem- 

 perature of 14 F. One even advances to 50 north latitude in 

 Canada. Mr. Dickinson, of Port Arlington, Victoria, observes 

 that many species are hardy in his neighbourhood, growing even in 

 sand, overtopping by 10 feet the Leptospermum Ia3vigatum and 

 breaking it down by their great weight within a few yards of the 

 sea. 



Opuntia Dillenii, Candolle. 



Central America. A Tuna-like Cactus, serving for uninflammable 

 hedges, and perhaps also for the rearing of the Coccus Cacti. It is 

 particularly eligible for barren land. 



Opuntia elatior, Miller. 



Central America. A hedge plant with formidable thorns. 



Opuntia Ficus Indica, Miller. 



Called inaptly, with other congeners, Indian Fig. Central 

 America, north as far as Florida. Serves for hedges. Pulp of 

 fruit edible. 



Opuntia Hernandezii, Candolle. 



Mexico. Affords also food for the Coccus Cacti. 



