354 OUTLINE OF PLANT GEOGRAPHY 



grown on a large .scale and is much the most important agricultural 

 product. Corn, oats, and barley are grown in considerable quan- 

 tities, and alfalfa is an important forage crop in many places. 

 Fruits and vegetables of many kinds thrive, and some fruit is ex- 

 ported, especially apples from Tasmania. Grapes, figs, passion- 

 fruit and oranges thrive in southern Australia, and wine of excel- 

 lent quality is an important product, especially in South Australia. 

 Dried fruits are made under much the same conditions as in 

 California, but as yet the industry is still on a relatively small 



scale. 



In Queensland sugar is grown in considerable quantities, and 

 tropical fruits, pineapples, bananas and papayas, are produced on 

 a commercial scale. 



The climate of New Zealand is too cool for tropical fruits, and 

 the cultivated fruits and vegetables are all the familiar ones of 

 the temperate zone. 



Weeds 



As in all other lands settled by Europeans, there have also 

 come many plant immigrants, not always welcome. These weeds 

 hail from many countries. In the hotter and dryer parts of Aus- 

 tralia, many of the weeds have come from India, Brazil or Africa, 

 while in the temperate parts of Australia and New Zealand, they 

 are the familiar European and American weeds, like sorrel, dock, 

 thistles, plantain, etc. 



Parts of Australia, especially Queensland, have been invaded 

 by the American prickly-pears (Opuntia spp.) which have proved 

 a very serious pest. It is said that in Queensland, 30,000,000 

 acres have been overrun by one species, causing immense damage. 

 America has also contributed the cockle-bur (Xanthium), Stramo- 

 nium and some other troublesome weeds. In the cooler and moister 

 parts of Australia and New Zealand, European blackberries, 

 sweet-brier, gorse and broom, have escaped from cultivation and 

 become very difficult to eradicate. 



South Africa, whose climate is so like that of Australia, has 

 contributed a number of plants which have become more or less 

 completely naturalized. The common calla lily may often be 

 seen growing in ditches in southern Australia, and several hand- 

 some South African Iridaceae, Ixia, Sparaxis, Watsonia and 



