Crataegus ROSACEAE Crataegus 



Crataegus L. Hawthorn. 



This is generally regarded as the most difl&cult genus of flowering 

 plants of eastern United States, from the standpoint of classifica- 

 tion, so that botanists have very generally neglected it. The 

 following treatment is chiefly based on C. S. Sargent's study of 

 "The Genus Crataegus in New Castle County, Delaware," the field 

 work for which was done by William M. Canby in the years 1900- 

 1903. Relatively few collections of Crataegus have been made in 

 other parts of our area. The writer has had the assistance of 

 Ernest J. Palmer, of the Arnold Arboretum, in the attempt to 

 bring the nomenclature of our species up to date. 



C. Crus-galli L. Cockspur Thorn. 



Common in the northern part of our area; some collections have 

 been made in the southern part: Ocean City (Wo), Canby, July 

 1891 (D); Chincoteague Island (Ac), R. R. Tatnall, 3792, 22 May 

 1938 (T). 



Var. p3n"acanthifolia Ait. 



Rather frequent in northern New Castle County. 



Var. oblongata Sarg. 



Infrequent; meadows in northern New Castle County. 



Var. capillata Sarg. 



Rare: roadside 1 mi. e. of Christiana, on the road to New 

 Castle, Canhy, 1 June & 26 Oct. 1901 (D), and 23 May 1903 (A). 



C. Canbyi Sarg. (Inch C. Pennypackeri Sarg.) 



Frequent in northern New Castle and Cecil Counties. 



The TYPE tree is, or was, "between Newport and Stanton" 



(NC), Canhy, 16 May & 16 Sept. 1899 (D). 



C. disperma Ashe. (C pausiaca Ashe.) Marshall's Thorn. 

 Rare: "meadows" (NC), Canhy, 10 Oct. 1902 (A). 



C. punctata Jacq. 



Infrequent; along streams in northern New Castle County. 



C. viridis L. 



Rather frequent, but seldom collected; in bottomlands of 

 streams, often growing in water: Choptank River, 1 mi. s. of Chop- 

 tank Mills (K), R. R. Tatnall, 2157, 3 June 1934, and several later 

 collections (T, A). 



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