302 MORPHOLOGY OF GYMNOSPERMS 



North America (including Mexico), southeastern Europe, and tem- 

 perate Asia. Thuja and Chamaecyparis belong to North America 

 and the China- Japan region, the former extending into central Asia; 

 and Thujopsis is endemic in Japan. Four genera belong to the 

 southern hemisphere, Actinostrobus and Callitris being restricted 

 to the Australasian region, Widdringtonia occurring in equatorial 

 and southern Africa, and Fitzroya with one species in southern Chili 

 and the other in Tasmania. Libocedrus girdles the Pacific, being the 

 only genus represented in both the northern and southern hemispheres, 

 the general outline of its range being California, Chili, New Zealand, 

 Australia, China, and Japan. 



The Araucarineae are exclusively southern, Agathis belonging 

 to the Malay Archipelago and the Pacific islands to New Zealand, 

 and Araucaria occurring not only in the Australasian region but also 

 in South America. This tribe is as characteristic of the southern 

 hemisphere as are the Abietineae of the northern hemisphere. 



By far the greatest display of Pinaceae in genera and species is 

 that which borders the Pacific Ocean, the chief areas being western 

 North America, the Australasian region, and the China- Japan region; 

 and throughout the whole of this vast border region Libocedrus is 

 represented. 



The China- Japan region is notable for its eight endemic genera, 

 six of which are monotypic (Pseudolarix, Sciadopitys, Cunninghamia, 

 Taiwania, CryptOmeria, and Thujopsis), and the remaining two are 

 each represented by two species (Keteleeria and Glyptostrobus). That 

 such an assemblage of the genera of Pinaceae should have been 

 preserved in this region after they had become extinct elsewhere is 

 remarkable. The wealth of the coniferous flora of this region may be 

 appreciated when it is understood that 87 species and 23 genera of 

 Coniferales have been recorded from China (113, 146), 42 of the 

 species being endemic; while in Japan 48 species are recorded, 15 of 

 which are endemic. 



Four of the genera of Pinaceae (Arthrotaxis, Actinostrobus, Calli- 

 tris, and Agathis) are endemic in the Australasian region; and three 

 (Pseudotsuga, Sequoia, and Taxodium) in North America. 



These general facts of modern distribution can only be understood 

 in connection with the more ancient distribution of genera and tribes, 



