1910.] NATURAL SCIENCES OF PHILADELPHIA. 247 



Corymbs and mature leaves glabrous. 



Flowers in many-flowered corymbs ; young leaves glabrous 



below; anthers white 3. C. tanwphylla. 



Flowers in few-flowered corymbs; young leaves villose 



below; anthers pink 4. C. propixa. 



Leaves subcoriaceous, with midribs and veins deeply impressed 

 on their upper surface. 

 Stamens 20; anthers pink. 



Pedicels stout, densely villose; leaves oblong-ovate to 

 obovate, acuminate, slightly hairy on the lower surface; 

 corymbs many-flowered; calyx-tube villose. 



5. C. succalenta. 



Pedicels slender, only slightly hairy; leaves obovate, mostly 



rounded at the apex; corymbs narrow, 10-1 5- flowered; 



calyx-tube glabrous 6. C. vaga. 



Stamens 10-15; anthers rose color; pedicels and leaves glabrous. 



7. C. kctifica. 

 Stamens 10 or less. 



Anthers pale pink; calyx-tube of the flower glabrous; fruit 



ovate 8. C. diaphora. 



Anthers yellow; calyx-tube of the flower slightly villose; 

 fruit subglobose to short-oblong 9. C. agaia. 



1. Crataegus tomentosa Linnaeus. 



Spec, 467 (1753); Sargent, Silva N. Am., IV, 101, t. 183; Proc. Rochester 

 Acad. Sci., IV, 132; Man., 492, f. 406; Proc Acad. Nat. Sci. Phila., 1905, 

 653; Rep. Geolog. Surv. Michigan, 1906, 560; No. 4 Ontario Nat. Sci. 

 Bull., 75; Rep. Missouri Bot. Gard., XIX, 116. 



Crataegus Ghapmani, var. Plukenetii Eggleston, Rhodora, X, 83 (190S); 

 Gray Man., ed. 7, 478. 



"Scottsdown Road," Allegheny County, J. A. Shafer, June 3, 1903; 

 also New York to Missouri and western North Carolina. 



2. Crataegus structilis Ashe. 



Jour. Elisha Mitchell Sci. Soc, XIX, 12 (1903); Sargent, Proc. Acad. Nat. 

 Sci. Phila., 1905, 656; Rep. Geolog. Surv. Michigan, 1906, 562; Bull. 

 Ont. Nat. Sci. Soc, 1908, 76; Bull. N. Y. State Mus., CXXII, 77. 



Orbisonia, Huntingdon County, B. H. Smith, (No. 311) May 20, 

 1906, October 8, 1907, B. H. Smith and C. S. Sargent, May 27, 1908; 

 also in Berks County, and in western New York to southern Ontario 

 and eastern Michigan. 



3. Crataegus tanuphylla n. sp. 



Glabrous with the exception of the hairs on the inner surface of 

 the calyx-lobes. Leaves oblong-obovate, acuminate, gradually nar- 

 rowed to the entire base, finely and often doubly serrate above, and 

 slightly divided above the middle into 4 or 5 pairs of small acuminate 

 lobes; more than half-grown when the flowers open and then thin, 

 dark dull yellow-green above and paler below, and at maturity 6-9 



