156 Proceedino;s of the Ohio State Academy of Science 



with gland-tipped teeth, or sometimes lobed. Conn, to Ind., Fla., 

 Ala., and Ohio. 



10. Crataegus macracantha Lodd. Longspine Hiaw- 

 thorn. A shrub or small tree with bright brown thorns, the 

 petioles glandular. Leaves sharply and often doubly serrate with 

 gland-tipped teeth. Quebec to N. Dak., Va., Mo., and Ohio. 



11. Crataegus mollis (T. & G.) Scheele. Downy Haw- 

 thorn. A small tree with short stout thorns and with densely 

 pubescent twigs. Leaves usually broadly ovate, incised and 

 sharply serrate with gland-tipped teeth. One of the best haw- 

 thorns. Quebec to Mich., Neb., Kan., Penn., La., Tex., and Ohio. 



12. Crataegus tomentosa L. Pear Hawthorn. A small 

 thickly branching tree with stout thorns and tomentose twigs. 

 Leaves broadly oval or ovate-oval, sharply dentate or somewhat 

 lobed. Ont. to N. J., Ga., Ohio, Mich., and Mo. 



13. Crataegus uniflora Muench. Dwarf Hawthorn. A 

 shrub or small tree, the branches with numerous slender thorns. 

 Leaves coriaceous, nearly sessile, crenate at the apex and entire 

 at the base. In sandy soil. N. Y. to Fla., W. Va., Mo., and La. 



Drupatae. Plum Subfamily. 



42. Prunus L. Plum, Apricot, Cherry. 



Trees or shrubs, the fruit a drupe, mostly edible. Leaves al- 

 ternate, simple, with glands on the petioles or at the base of the 

 blade; some of the leaves often without glands. Terminal bud 

 sometimes self-pruned, and in some species also twigs of various 

 sizes. 



1. Flowers in lateral umbellate clusters or somewhat corymbose, ex- 

 panding with or before the leaves : stone flattened or globular ; 

 terminal bud of twigs absent or present. 2. 



1 . Flowers in racemes, terminating twigs of the season ; stone globular ; 

 terminal bud of twigs present. 9. 



1. Flowers corymbose, terminating twigs of the season; leaves ovate, 

 abruptly acute at the apex, rounded or slightly cordate at the base; 

 fruit small, stone slightly flattened ; terminal bud of twigs present. 

 P. mahaleb. 



