HISTORY OF THE WILLOWS AND POPLARS 19 



grades are largely used for box and cooperage material while 

 the higher grades are employed for furniture drawers and back- 

 ing, as well as for refrigerators, cabinet work and cheap furni- 

 ture. Willow planking is satisfactory for purposes where strength 

 is not required, since it does not warp, splinter or check, and this 

 property determines its use for boat parts such as keels, paddles, 

 etc., and for athletic goods, cutting boards, toys, etc. Large 

 quantities are also consumed every year by excelsior mills. 



The oldest known willows, not certainly identified, are re- 

 corded, along with the early representatives of other dicotyledon- 

 ous plants, from the Lower Cretaceous of Portugal. During 

 the earlier part of the Upper Cretaceous, the time when the 

 remains of the higher or socalled flowering plants first become 

 prominent in the geological record, a great manj^ species of un- 

 doubted willows have been found. Upwards of a score of forms 

 have been described and the ancestral stock during these early 

 daj^s must have possessed some of the ^dtalitj^ that marks the 

 recent forms for it spread rapidly over North America as well 

 as Europe and probably over Asia as well, although there are 

 no known records from the last continent. It should be noted 

 that four-fifths of the known Cretaceous species, are North 

 American and that none have been found in the prolific Cretace- 

 ous plant beds of Greenland, although poplars were abundant 

 at that time in the far north. 



Botanists are divided in their interpretation of the willow 

 flower, some regarding its simplicity as a primitive character 

 and others regarding it as reduced by evolution from more 

 evolved types. Whichever view is correct the willows undoubt- 

 edly appear early in the geological record and there is absolutely 

 no basis for regarding the terminal wood parenchyma as support- 

 ing the reduction theory, as is done by Holden.^ 



The oldest Tertiary, or Eocene, deposits have furnished about 

 25 species of willows, the records including all of the continents 

 of the Northern Hemisphere. Willows had now reached Green- 

 land, where five different species have been discovered. Other 



1 Holden, R., Ann. Bot. 26: 17L 1912. 



