DRUPACEAE 177 



11. Crataegus macracantha Lodd. Long-spined Thorn. (Man. 

 p. 521 ; I. F. f. 2000.) In woods, Quebec to N. Dak., Va., and Mo. — 

 Pemisylvaftia : Northampton ; Bucks ; Lebanon ; Delaware. 



12. Cratageus mollis (T.&G.)Scheele. Red-fruiTEd Thorn. (Man. 

 p. 521 ; I. F. f. 2001. ) Thickets, Quebec to Mich., Neb.,Kans., Pa., La. 

 and Tex. — Pennsylvania : York ; Huntingdon ; Allegheny. 



13. Crataegus Biltmoreana Beadle. Biltmore Thorn. (Man. p. 

 521.) In woods. Pa. to N. C, Ala. and Mo. — Pennsylvania : Monroe, 

 2 m. south of Stroudsburg ; Bucks. 



14. Crataegus tomentosa L. Pear-Thorn. Pear Haw. (Man. p. 

 522; I. F. /. 2002.) In thickets, Ont. to N. J., Ga. Mich, and Mo.— 

 Pennsylvania : Northampton ; Bucks ; Lancaster ; Columbia ; 

 Franklin ; Huntingdon ; Sullivan ; Allegheny. 



15. Crataegus Vailiae Britton. Vail'S Haw. (Man. p. 522 ; I. F./ 

 200$. ) In thickets, Pa. to N. C. — Pennsylvania : Delaware. 



16. Crataegus uniflora Muench. Dwarf Thorn. (Man. p. 522; I. 

 F. /. 2004.) In sandy soil, N. Y. to Fla., W. Va., Mo. and \^2l.— Penn- 

 sylvania : Northampton ; Bucks ; Delaware ; Montour ; Chester ; 

 Franklin. 



7. COTONE ASTER Medic. 



1. Cotoneaster Pyracantha (L. ) Spach. Evergreen or Fire 

 Thorn. (Man. p. 522 ; I. F. f. 2006.) In thickets, escaped from cult. 

 Native of Europe. — Pennsylvania : Bucks, Doylestown ; Philadelphia. 



Family 13. DRUPACEAE DC. Plum Family. 

 Drupe glabrous : stone not corrugated. i. Prunus. 



Drup'e velvety : stone corrugated. 2. Amygdalus. 



1. PRUNUS L. 



A. Flowers in corymbs or umbellate clusters from the branches of the preced- 

 ing year, before the leaves. 

 a. Inflorescence umbel-like : drupes over 7.5 mm. in diameter. 

 Leaves convolute in vernation. 

 Umbel-like clusters several-flowered. 



Drupe red or orange, without a bloom, mostly over 20 mm. thick. 



1. P. Americana. 

 Drupe purple, with a bloom, mostly less than 15 mm. thick. 



2. P. Alleghe7iiensis. 

 Umbel-like clusters 1-2-flowered. 3. P. spinosa. 



Leaves conduplicate in vernation. 

 Large trees : corolla 1.5-3 c^i- wide : leaf-blades sharply serrate : drupes 

 mostly over 10 mm. in diameter. 

 Drupe sour : leaves glabrous. 4. P. Cerasus. 



Drupe sweet : leaves pubescent. 5. P. Avium. 



Low spreading shrubs : corolla about i cm. broad : leaf-blades appressed- 

 serrate : drupes mostly less than 10 mm. in diameter. 

 Leaf -blades typically oval or oblong. 6. P. cuneata. 



Leaf-blades typically oblanceolate or spatulate. 7. P. piimila. 

 12 



