-35- 



Much more field work and collecting is necessary to validate 

 the exact present status of each species of rare and restricted 

 plant. Extensive field work is required to prove whether or not 

 certain plant species have become extinct. 



Range Phenomena 



Plant and animal species usually have distinct areas where 

 the major populations occur. But at the edges of the range there 

 may be outliers or disjunct populations which may have developed 

 taxonomic or other differences if they have been isolated for some 

 time. They may include both new endemic or old relict populations 

 of scientific importance and often need protection. At the edges 

 of ranges, species may be rare and require protection. 



Because of its position halfway up the Atlantic Coastal Plain, 

 the Bay region includes many edges of ranges or outlying disjunct 

 populations. 



Northern Limit . Many species with an essentially southern 

 distribution extend into the Bay region; e.g., longleaf pine 

 ( Pinus palustris ) and water tupelo ( Nyssa aquatica ) . 



Northern Outlier . Some southern species have disjunct 

 populations, often just a few individuals, well north of the contig- 

 uous populations: e.g., bald cypress ( Taxodium distichum ) , water 

 hickory ( Carya aquatica ) , overcup oak ( Quercus lyrata ) , and live oak 

 ( Quercus virginiana ) . 



