62 ESSAYS. . 



are well formed and filled with ovules, which, however, so far 

 as I have observed, are never fertilized ; and the stigmas are 

 smaller than in the fertile plant, and not papillose. In the 

 other or fertile form, both the stamens and the petals are in 

 an abortive or rudimentary state, and being shorter than the 

 sepals, and concealed by them in dried specimens, are readily 

 overlooked ; the stigmas are large, truncate, and papillose, 

 and a portion of the ovules become fertile. The Japanese 

 species (Hoteia Japonica, Morr. & Decaisne, the Spirceu 

 Aruncus of Thunberg) appears to have uniform and perfect 

 flowers 5 1 but the species from Nepal {Astilbe rivularis, Don, 

 the Spiraea barbata of W allien, but not of Lindley) is prob- 

 ably polygamo-dioecious, like our own species ; at least, the 

 flowers are apetalous in a fragment given me by Professor 

 Royle, and the stamens mostly equal in number to the sepals. 

 I have no doubt that these three species belong to a single 

 and very natural genus, for which the name of Astilbe must 

 be retained ; for I see neither justice nor reason in supersed- 

 ing the prior name, as suggested by Endlicher, 2 on account of 

 the incompleteness of the character, which correctly describes 

 one state, at least, of the plant intended, by the subsequent 

 Hoteia, the character of which is equally incomplete, when 

 applied to the whole genus. The number of genera which 

 are either divided between North America, Japan, and the 

 mountain region of central Asia, or have nearly allied species 

 in these countries or in the two former, is very considerable : 

 in other cases a North American genus is replaced by a 

 nearly allied one in Japan, etc., as Decumaria by Schizo- 

 phragma, Schizandra by Sphaerostemma, Hamamelis by Cory- 

 lopsis, etc. I have elsewhere alluded to this subject and shall 

 probably consider it more particularly on some future occasion. 

 Our next day's journey was from Cranberry Forge to Crab 



1 " Flores in meo Japonico specimine omnes inveni hermaphroditos, 

 nee ullos polygamos." (Thunberg, " Flora Japonica," p. 212, sub Spircea 

 Arunco.) 



2 " Si, quod nunc asserunt auctores, Hoteia et Astilbe, Don, revera 

 plantse congeneres, posterius incomplete ad auctore suo descriptum sup- 

 primendum, et prius egregie stabilitum servandum erit." (Endlicher, 

 " Genera," Suppl. p. 1416.) 



