6 



A STUDY OF THE SPECIES. 19 



shade, but the species ^loes not retain this characteristic late in life. 

 The ease with which young trees are injured by fire is counterbalanced 

 by their abilit} T to sprout. The large trees are generally decayed, and 

 many of them have dead tops, killed by insects and fungi, which have 

 followed injury b} T fire. 



Yellow Oak is common to all situations and soils at Sewanee. It 

 forms a large tree with short, clear bole, and large crown. The largest 

 tree measured was 10 inches in diameter. On-the plateau it occasion- 

 ally occurs in groups on Oak Flat, but its usual distribution is by single 

 trees. Yellow Oak seeds plentifully every few years. Seedlings start 

 profusely, but seldom attain good size before they are burned or 

 browsed. The tree sprouts freely, and much of the plateau under- 

 growth is Yellow Oak suckers. The large Yellow Oaks on the plateau 

 are usually hollow, and the species is much harmed by borers and 

 defoliators. 



Black Jack is limited to groups of scrubby trees near the edge of 

 the plateau. It grows on the poorest, most gravelly places. The 

 largest specimen seen measured 6 inches in diameter and 25 feet in 

 height. The tree yields many acorns every other year, but there is 

 practically no reproduction. Bushes of sprouts are common in open 

 places near the old trees. Fire is the main source of injury, as the 

 tree is not lumbered and cattle generally leave it alone. 



Slippery Elm, demands a deep, fertile soil. It occurs on Northerly 

 Slope as a short tree, less than 6 inches in diameter. It produces a 

 scant crop of seed about once in five years. There is no reproduction. 

 All the trees seen were growing in the shade. 



White Elm is scattered on Northerly Slope benches, forming a tall, 

 straight tree, with a long, narrow crown. It requires good, moist soil. 

 The largest tree measured was 25 inches in diameter; the average was 

 11 inches. White Elm seeds abundantly and often, but no young 

 growth was observed. High pole trees are growing vigorously under 

 shade. The leaves of many of the Sewanee Elms have been eaten by 

 insects. 



Cork Elm grows in the gravel along the bluffs, where it does not 

 reach a good size and is always crooked. The largest tree measured 

 had a diameter of 9 inches. Scrubby seedlings occur near the older 

 trees. 



Whig Elm is occasionally met with on Chestnut Ridge as a low shrub, 

 but makes a much better tree in the rich, moist soil of Northerly 

 Slope, where a specimen 7 inches in diameter was measured. Seed- 

 lings were observed only in the better situations, where light had 

 penetrated. 



Cucumber-tree mingles with White Basswood, White Ash, and White 

 Elm in the fertile, moist soil of Northerly Slope. It develops a rather 

 short, scraggly crown, and a long, clear, slender bole. The largest tree 



