160 JOURNAL OF THE ARNOLD ARBORETTM [vol. v 



latter are usually rounded at base and those of the former cuneate can 

 hardly he considered a sufficient character and moreover the shape of the 

 base is not constant as no. 13*23 of var. setchuenensis shows which has 

 cuneate leaves. All the specimens of Giraldi\s collection received from 

 the Herbarium in Florence under the name H. Giraldii had the underside 

 of the leaves nearly glabrous and have been referred here to the preceding 

 variety. 



Hydrangea xanthonenra and //. Bretschneideri are very closely related 

 ;uid both vary with pubescent and glabrescent leaves; the only reliable 

 character to distinguish these two species is apparently the behavior of 

 the bark which, in 77. Bretschneideri, separates the second year in thin 

 large flakes and is of chestnut-brown color without or with few incon- 

 spicuous lenticels, while in H . xanthonenra the bark adheres to the branch, 

 is conspicuously lenticellate and varies from yellowish gray to red-brown 

 in color. 



Hydrangea longipes Franchet in Nouv. Arch. Mus. Paris, ser. 2, vin. 



228 (PL David, it. 45) (1885).— Rehder in Sargent, PL Wilson, l. 33 



(1913).— Hers in Jour. N. China Branch R. As. Soc. LIU. Ill (1922); Liste 



Ess. Lign. Honan, 11 (1922). 



Hydrangea Hemsleyana Diels in Bot. Jahrb. xxix. 376 (1900). 



Honan: Sung hsien, San kuan miao, ./. Hers, no. 551, May 24, 1919; 

 Lushih, Hiung eul shan, alt. 1400 m., J. Hers, no. 938, October 10, 1908. — 

 See also Hers, L c. 



Shensi: Kin quan san, G. Giraldi, July 10, 1897; Tai pei shan, W. 

 Purdom, no. 977, 1910. — See also Diels, 1. c. 



Distribution: also Hupeh, Szechuan. 



Hydrangea Rosthornii Diels in Bot. Jahrb. xxix. 874 (1900). 



Honan: Lushih, Hiung eul shan, alt. 1300 m., ♦/. Hers, no. 871, October 

 9, 1919. 



Distribution: also Szechuan. 



Hers* specimen referred here to //. Rosthornii may possibly be nothing 

 but a very vigorous and more pubescent form of //. longipes but it certainly 

 matches better the material of H. Rosthornii before me than that of //. 

 longipes. As in the case of //. Bretschneideri and //. xanthonenra we have 

 here a group of closely related very variable species namely H. strigosa 

 Rehd., //. longipes and //. Rosthornii, which though very distinct in their 

 extreme forms seem to merge into each other and are difficult to define. 



Hydrangea macrophylla De Candolle, Prodr. iv. 15 (1830). — Wilson 



in Jour. Arnold Arb. iv. 234 (1923). 



Hydrangea "Hortensie" Faber in Denkschr. Entwickel. Kiautschou, 31 



(1898). 

 Hydrangea spec. "Hortensie" (lilg & Koehne in Bot. Jahrb. xxxiv. beibl. 

 lxxv. 39 (1904). — Loesener in Hot. Centralbl. Beih. xxxvn. abt. n. 130 



(1919). 



NTUNC 



1. a). 



