l8 NEW YORK STATE MUSEUM 



fruit, however, is quite different from the fruit of that species and 

 is much later in ripening. Spines are almost entirely absent from 

 the branches. In the North Albany clump only two small ones 

 were found; in the Wynantskill clump none was found on the living 

 branches and only three on one dead twig. In a third clump no 

 spines are present. 



Crataegus casta Sarg. 

 The chaste thorn belongs to the large group Pruinosae and to a 

 possible section in which the flowers have 20 stamens with pink 

 anthers. The fruit is beautifully colored and its pointed base af- 

 fords an available character by which to distinguish the species 

 from its near allies. 



Crataegus conspicua Sarg. 

 The conspicuous thorn is a large shrub quite distinct from our 

 other species of this group by its very hairy inflorescence and by the 

 hair}^ lower surface of the leaves. The fruit persists till late in the 

 season and sometimes a considerable part of it hangs on the branches 

 through the winter. 



Crataegus contortifolia Sarg, 

 The twisted-leaved thorn takes its name from one of the easily 

 recognized and distinguishing characters of the species. This 

 consists in a peculiar folding or wavelike curving of the margin of 

 the leaf, as if there was a superabundant formation of marginal 

 tissue for which there was no room in the ordinary plane of the leaf. 

 This results in the curving of the margin. Such leaves do not press 

 fiat and smooth in the plant press. The species has affinities with 

 C. champlainensis.C. submollis, C. tatnal- 

 liana and C. arnoldiana, but with none of them does it 

 satisfactorily agree. It was erroneously referred to C . t a t n a 1 - 

 liana in New York State Museum Bulletin 94, page 28. 



Crataegus demissa Sarg. 

 The low thorn grows from 4 to 6 feet tall and has small leaves, 

 small flowers and small fruit. It is quite diminutive in all its parts 

 and easily recognized. 



Crataegus divergens Sarg. 

 The divergent thorn was formerly considered a variety of the un- 

 shaven thorn, C . i r r a s a , but it is now deemed worthy of specific 

 distinction. It grows in patches rather than in clumps. 



