206 Rhodora [Siptbmbbb 



In the course of this study the author has used the collections of 

 the Gray Herbarium, the Arnold Arboretum, Columbia College 

 Herbarium, the Herbarium of the New York Botanical Garden, the 

 California Academy of Sciences, and the private herbaria of Mr. C. 

 C. Deam, Mr. Walter Deane, and Mr. F. W. Hunnewell. To Dr. 

 B. L. Robinson, Dr. J. K. Small, Mr. C. C. Deam, ami Mr. J. C. Nel- 

 son, he is ndebted for extended loans of specimens or hooks. Speci- 

 mens art* cited from each state where they have been collected, but 

 in most cases only one from each state is listed. 



The following notation is used to indicate the location of a cited 

 specimen: 



(C) = Columbia College Herbarium 

 (Cal) = California Academy of Sciences 



(D) = Herbarium of Mr. C. C. Deam 



(G) = Gray Herbarium of Harvard University 



(N) = Herbarium of the New York Botanical Garden 



KlOV TO BtDBANOBA ARBORBSCBN8 AND ITS VARIATIONS. 



A. Loaves nearly glabrous beneath, the scanty puberulence 

 confined to the principal nerves. 

 B. Leaves cordate or rounded at base, broadly ovate or 

 suborbicular with an acuminate tip. 



C. Some or all of the flowers fertile 1. //. arboreaceru L. 



C. All of the flowers sterile and radiant 2. f. grandiflora Render. 



B'. Leaves oblique at base, lance-ovate or lance-elliptic. 



I). Some or all of the flowers fertile 3. var. oblonga T. it ( i. 



I)'. All of the flowers sterile and radiant. . .4. f. stcrilis (T. it (J.) St. John 

 A'. Leaves closely short-puberulent beneath, all of the secon- 

 dary nerves bearing hairs, cordate or rounded at base, 

 broadly ovate or suborbicular, acuminate at tip. 



10. Some or all of the flowers fertile f>. var. Ihamii St John 



E'. Most all of the flowers sterile and radiant (i. f. acarpa X\. John 



I. Hydrangea arborescens L., Sp. 1*1. i. 397 (1753); //. vulgaris 

 Mich*., Fl. Bor.-Am. i. 268 (1803); //. cordata Pursh, Fl. Am, 

 Sept. i. 309 (1816); //. ctdgaris Michx., [j cantata (Pursh) Torr., 

 Ann. Lye. N. Y. ii. 205 (1827); //. arborescens L., var. vulgaris (Michx.) 

 Ser., DC. Prodr. iv. 14 (1830); //. arborescms L., $ cordata (Pursh) 

 T. & (r., Fl. N. Am. i. 591 (1838-1840); //. arborescent L., f. typica 

 Schneider, III. Handb. d. Laubholzk. i. 387 (1905); //. arborescms L., 

 f. vulgaris (Michx.) Schneider, 1. e. 387; //. arborescens L., var. typica 

 Schneider, 111. Handb. d. Laubholzk. ii. 943 (1912). 



Distribution: New York: Wellsburg Narrows, Chemung Co., 

 July 2, 189G, September 17, 1897, T. F. Lucy, no. 5,490 (N). Penn- 

 sylvania: Nescopee, Luzerne Co., July 2, 18S9, A. A. Heller (G.). 



