22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



As a matter of fact tree ferns reach their maximum development 

 m temperate rain forests, as in New Zealand (Lat. 40° S.), or in 

 similar situations in tropical uplands, as was pointed out by Alexander 

 von Humboldt over 100 years ago. They reach their greatest pro- 

 fusion in South America in the temperate part of the montana zone 

 of the eastern Andes. They grow luxuriantly on the mountains of 

 central Africa at altitudes where they are buried in snow for part of 

 each year, and as fossils their climatic significance is wet temperate 

 and not tropical. 



There are a great many other genera or species in the same category. 

 I have seen Anonas and Ingas (cultivated) at 10,000 feet in the Andes 

 perfectly hardy, and a large nvmiber of generic types that are com- 

 monly thought of as lowland tropical above the tropical altitudinal 

 zone — such things as Dodonaca viscosa, Sapiudus sapoiiaria and 

 Szmctcnia viahagoui. In fact it was my own observations in the Andes 

 that first turned me from the paleobotanic tropical tradition. 



Another misinterpreted type is the Gleichenia type of ferns (now 

 segregated in several genera) very common in the Cretaceous floras 

 of Greenland, but largely absent from the northern hemisphere in 

 recent floras. Although commonly confined to low latitudes at the 

 present time, it is by no means confined to the tropical altitudinal 

 zone; in fact, where I have seen it (Yungus of Bolivia) it is promi- 

 nent above the tropical zone, as it is also in Hawaii, Peru, Ecuador, 

 Asia, etc. Representatives reach 54° South in Chile and 40° South 

 in New Zealand. 



All this is related in any account of fern distril)ution (e.g., Die 

 natiirlichen Pflanzenfamilien, 1902), and still Gleichenias, along with 

 palms, cycads, and tree ferns always appear in the paleobotanists 

 tropical repertoire. 



I suppose that constant reiteration of facts like the foregoing will 

 have to be continued over many years before the news reaches those 

 who write on paleoclimatology, and at least another generation will 

 elapse before writers of geological text books cease to talk about the 

 tropical climate of Tertiary Greenland. 



Juniperus communis Linne is found as far north as the North Cape, 

 which is at least 20° farther north than any other member of the 

 family Cupressinaceae is found in the Eastern Hemisphere (Nat- 

 borst, T911). Sassafras, of the mostly tropical family Lauraceae. ex- 

 tends northward to southern Maine, or about 13° beyond the bulk 

 of the family. Diospyros, of the mostly tropical family Ebenaceae, 

 extends northward to southern Connecticut, or about 12° beyond the 

 bulk of the family. 



