vn. 



In many instances those whom the Commission consulted had been 

 accustomed to regard 1(tie prickly-pear as a botanical species, or as an economic 

 plant serving one use or another, and could therefore scarcely be brought to 

 regard it from the present Australian standpoint. The Commission was, how- 

 ever, greatly aided in dealing with this emergency, and in bringing home to 

 its auditors the actual state of affairs in Australia with regard to it by an 

 excellent series of photographs illustrating the different species of Queensland 

 " pears," as well as their habits of growth and mode of occurrence, which had 

 been procured by Mr. Temple Clerk, of, the Department of Public Lands, 

 Queensland, and considerately made available by him. 



The Commission had been asked to visit both those countries where 

 prickly-pears were indigenous and those in which these plants were naturalised. 

 To have carried out that itinerary in its entirety would have involved a very 

 protracted inquiry. Hence many countries were omitted, owing to the difficulties 

 in reaching them — e.g., Bolivia, Peru, Northern Chile, Northern Argentina, 

 Central America, many of the smaller West Indian Islands, as well as certain 

 parts of the Mediterranean region. The civil war in Mexico, especially in the 

 dry northern States, where the cactus flora is so rich, prevented the Commission 

 from pursuing inquiries there, and consequently only a few of the cities within 

 the northern frontier of Mexico were visited. 



THE PRICKLY-PEARS NATURALISED IN AUSTRALIA. 



There are at present naturalised in Queensland not less than eleven 

 species of prickly-pear, viz. : — 



1. The common pest pear, Opuntia inermis, DC, var. Its home is in the 

 Greater Antilles (West Indies) and the adjacent coasts of the United States 

 (Florida). 



2. The spiny pest pear- — an ally of that just named — ^which is especially 

 prevalent in the Gayndah District, and occurs also in the Rockhampton area 

 and elsewhere. It is this species which Mr, Maiden has identified in error as 

 0. dillenii. It is also a West Indian plant. 



3. 0. monacantha, Haw. — ^A tree pear which occurs along the banks of 

 the Suttor River, North Rockhampton, and elsewhere ; but except in the 

 localities named is sparsely distributed. Its home is Eastern and South-eastern 

 Brazil and adjacent parts of the neighbouring Republics. This species prefers 

 moister and more shaded conditions than do the other opuntias now occurring 

 in Australia. 



4. 0, aurantiaca, GiUies. — This low-growing, very brittle plant, which 

 occurs at Warwick and Roma, is the dreaded " jointed cactus" of South Africa. 

 It should be immediately eradicated from our State by vigorous methods, such 

 as systematic spraying and burning. Owing to the extreme ease with which the 

 small spiny joints and fruits become separated and conveyed by flood water, 

 and, moreover, attached to animals, the species is likely to become widely spread. 

 By reason of its generally small size, the plant is likely to be overlooked until 

 such time as it has obtained a strong foothold. It is a native of Uruguay, in 

 South America. 



5. 0. tomentosa, S.D. — This " tree pear " may be found commonly in the 

 Helidon District, and is especially prevalent in the Gogango District, a few miles 

 west of Rockhampton, and to a less extent near Gayndah. Its home is Mexico. 

 This plant is used in some countries as a " nurse" for raising the true cochineal. 



6. Nopalea cochinelifera, Linn.—" The cochineal plant " ; is also a tree 

 pear, and may be found at Gayndah and Emerald. It is spineless and cannot 

 be considered a pest. Its home is, doubtless, in Mexico. 



