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tlbe flora of the Mabasb Dalle^.* 



THE composition of the remarkable forests which, in spite of 

 the terrible inroads that have been made in them during 

 the last twenty-five years, still cover considerable portions 

 of the region in southern Illinois and Indiana watered by the 

 Wabash River and its tributaries, was first made known to the 

 scientific world by a paper published in 1882 in the fifth volume 

 of the Proceedings of the United States National Museum, by Dr. 

 Robert Ridgway, the ornithologist of the Smithsonian Institution. 



In a second paper on the Wabash Silva, recently published in 

 the seventeenth volume of the Proceedings of the Natio?ial Museum, 

 Professor Ridgway shows that the number of indigenous arbores- 

 cent species in the Wabash valley south of the mouth of White 

 River is one hundred and seven, or more than a quarter of all the 

 arborescent species in N. America north of Mexico, and even this 

 number can be slightly increased, as one or two species of Cratce- 

 gusy overlooked by Professor Ridgway, grow near Mount Carmel. 



Some idea of the surprising richness of the forest-flora in this 

 region can be obtained by an examination of Dr. Ridgway's 

 list of trees growing on restricted areas. On a tract of seventy- 

 five acres he found fifty-four species of trees, and another of 

 twenty-two acres contained forty-three species. On a tract of 

 forty acres one mile south-east of Olney, in Richland County, 

 lUinois, what the author modestly calls an imperfect survey of the 

 woods shows thirty-six species. The nearest approach to such a 

 concentration of tree species in a restricted area is in central Yezo, 

 where Professor Sargent found sixty-two species and varieties of 

 trees growing in the immediate neighbourhood of Sapporo at 

 practically one level above the sea. 



The height attained by these Wabash valley trees is as remark- 

 able as the number of species in the forest. Individuals of forty- 

 two species reach a height of one hundred feet, and those of 

 twenty-one species grow to the height of one hundred and thirty 

 feet. Individuals of one hundred and fifty feet high of thirteen of 

 these species have been measured. A specimen of Quercus 



* From Garden and Forest^ March 13, 1895. 



