CHECK LIST OF FOREST TREES 135 



Note on nomenclature. — Formerly included under Amelanchier alnifolia 

 Nuttall, which, as now understood, is a shrub. 



NAMES IN USE 



Pigeon Berry (So. Oreg.). Sarvice (Colo., Utah., Wyo.). 



Serviceberry (Colo., Calif.). Sarviceberry (Colo., Idaho). 



Western Serviceberry. Saskatoon. 



Rocky Mountain Service Tree (lit.). 



CRATAEGUS Linmeus 56 

 GROUP I: OXYCANTILE Loudon 



Cratsegus oxycantha Linnaeus. English Hawthorn. 



Range. — Native of Europe. Widely cultivated and naturalized in a few 

 localities in the eastern United States. 



names in use 



English Hawthorn. Quick-set-Thorn. 



Quick. 



GROUP 2: CRUS-GAILI Loudon 



Crataegus crus-galli Linnaeus. Cockspur Thorn. 



Range. — From the St. Lawrence River (near Montreal) southward to Dela- 

 ware and in the Appalachian foothills to North Carolina; westward through 

 western New York and Pennsylvania to southern Michigan. 



NAMES IN USE 



Cockspur Thorn (Vt., N. H., R. I., Thorn (Pa.). 



N. Y., N. J., Pa., Del., W. Va., Pin Thorn. 



N. C, Ont.). Thorn Plum (Me.). 



Red Haw (Mich.). Cockspur Hawthorn (Pa.). 



Newcastle Thorn (Del.). Hawthorn (Pa.). 



Thorn Apple (N. Y.). Haw. 



Thorn Bush (Pa.). 



i5 In 1S98, when the first edition of the Check List was issued, the number of different native and nat- 

 uralized species of Cratxgus then recognized did not exceed 25. At the present time there are probably at 

 least 197 known arborescent species, together with approximately 100 shrubby hawthorns. Eastern United 

 States and adjacent sections of Canada have yielded the great majority of these species. 



With the exceptiou of the genus Eucalyptus, doubtless Cratxgus is the most difficult group of woody 

 plants. The distinctions relied upon to separate many of the species include the color and number of 

 stamens, form and color of the fruit, the number and markings of its seeds, etc., all of which require carefully 

 collected sets of specimens, taken from the same individual plant, from the early flowering to fruiting stages. 

 Most of these characteristics are quite beyond the lay student of trees, while they are exceedingly difficult 

 even for technically trained observers. Perhaps less than 25 of our native hawthorns could be accurately 

 distinguished by the layman. Later studies may show also that a good many of the hawthorns now 

 regarded as species are actually of hybrid origin. Years of study and painstaking investigation in growing 

 plants from seed will be required before this most perplexing group can be fully understood. 



The first edition of Professor Sargent's Manual of the Trees of North America (1905) contains descrip- 

 tions of 132 species of Crataegus, and the new edition of his Manual contains 153 arborescent species. N. L. 

 Britton and J. A. Shafer have described and figured 51 species of Cratxgus in their work on North American 

 Trees (1908). These are the only two works attempting to describe all of the known species of Cratxgus 

 growing in North America. 



Of the regional floras which collectively deal with our hawthorns, Asa Gray's New Manual of Botany 

 (1908) gives 65 species, only 5 being noted as trees; while J. K. Small in the last edition of his Flora of South- 

 eastern United States (1913) described 184 species of this genus, of which 142 are ranked as trees. P. A. 

 Rydberg's Flora of the Rocky Mountains and Adjacent Plains (1917) contains 8 species of Cratxgus, all of 

 which are trees. In his Silva of California (1910) W. L. Jepson admits a shrubby species for California, and 

 Charles V. Piper and R. Kent Beattie in their Flora of the Northwest Coast (1915) record one species as a 

 shrub, which elsewhere, however, is a tree. The total number of tree hawthorns recorded in these regional 

 floras is 259, of which 155 are ranked as trees. 



Necessarily the ranges given for many species have not been fully determined, the information now 

 available often being rather fragmentary. Much further careful study is necessary before the ranges of 

 species now known are fully understood. 



The species of this genus are variously referred to as hawthorns, thorns, and thornapples. 



