in Extra-Troj)ical Countries. 239 



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. O. 

 montana (De Candolle) is a dwarfer sub-alpine variety of limestone- 

 regions. 



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



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

 red dye. 



Ophiopogon Japonicus, Ker. (Flueggea Japonica, Richard.) 



The mucilaginous tubers can be used for food, a remark, which 

 applies to many other as yet disregarded allied plants. 



Opuntia coccinellifera, Miller. 



Mexico and West-Indies. The Cochineal-Cactus. On this and 

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

 cus, which affords the costly cochineal-dye. Three gatherings can 

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

 nually into Britain alone, and a good deal to other countries, valued 

 at about 400 per ton. The precious carmin- pigment is prepared 

 from cochineal. Different Cochineal-Opuntias occur in Argentina 

 also. Some species of Opuntia will endure a temperature of 14 F.; 

 one even advances to 50 north latitude in Canada. Mr. Dickinson 

 observes, that many species are hardy at Port Phillip, growing even 

 in sand, overtopping by 10 feet the Leptospermum laevigatum, and 

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

 sea. 



Opuntia Dillenii, De 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, but apt to stray beyond bounds in 

 'hot countries. 



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 big hedges. Pulp of fruit 

 edible. Exudes a gum, somewhat like Tragacanth. 



Opuntia Hernandezii, De Candolle. 



Mexico. Also affords food for the Coccus Cacti. 



Opuntia Missouriensis, De Candolle. 



From Nebraska to New Mexico. Very hardy. Professor Meehan 

 found this Cactus covered with the Cochineal Coccus, and points to 

 the fact, that this insect will live through the intense cold, which 

 characterizes the rocky mountains of the Colorado-regions. 



