Bunch Grass 



A grass which forms a tuft or bunch, many stems arising 

 from the root-crown in a dense mass, e.g., orchard grass, 

 bluestems. 



Bunt Order 



Rank of dehorned cattle in a herd, determined by aggres- 

 sive behaviour. 



Buoyancy Theory 



An explanation of the role of morphological features that 

 decrease the rate of sinking of plankton. 



Buried Soil 



One or more layers of soil which was formerly at the 

 surface followed by covering with ash, sand, or some other 

 form of deposition. 



Burn Scar 



A scar on a tree where the tissues were damaged by fire, 

 it may be partly or entirely covered by later-formed tissues. 



Bush 



(1) a shrub. (2) An area covered by shrubs or forest, 

 especially in Australia and South Africa; also used for any 

 uncleared land. 



Butte 



An isolated hill with steep sides and a comparatively 

 flat top, smaller than a Mesa, term used in western United 

 States especially. 



Buttress 



A lateral plank-like extension near the base of some trees, 

 gives additional support to the tree. 



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