124 BOTANICAL EXCURSION IN SOUTH CAROLINA. 
ter of which is equally deficient, when applied to the whole - 
genus.* The number of genera which are either divided 2 
between North America, Japan, and the mountain-region : 
of central Asia, or have nearly allied species in these coun- 
tries or in the two former, is very considerable: in other j 
cases, a North American genus is replaced by a nearly allied a 
* Since the above remarks were written, I have seen, in the Annales 5 
des Sciences Naturelles, Jan. 1841, M. Decaisne's additional Note sur n j 
genres Astilbe et Hoteia, in which the two genera are still held to be dis- 
tinct, the latter including the North American plant, as originally pro- — - 
posed by this author. The characters of his two genera (excluding such 
as are common to both) are merely these: E 
Astilbe. Flores hermaphroditi, vel sepe stam. abortu foeminel. Petala 
nulla. Stamina 5, 2 
Hoteia. Flores hermaphroditi, Petala 5, angusta, Stamina 10, quin- 
que petalis opposita breviora. i 
Since, then, it appears that the Astilbe rivularis is more or less dicecio- 
polygamous, the view I had already taken is certainly confirmed; and 
when this acute and justly distinguished botanist becomes acquainted with 
the two states of the American species, and considers that the stamens 9 
the original Astilbe are probably sometimes double the nember of the 
sepals, as described by Don, he will doubtless come to the same conclusion. 
The diagnostic characters of the 3 species may be thus expressed. 
 AsriLBE, Ham., ez Dou, Torr. et Gray. (Hoteia, Morr. et Decaisne). — 
1. A, rivularis (Hamilton, Don): floribus sepe dicecio-polygamis, di 
lyce 4-5 partito imo ovario tantum adnato, petalis (an semper?) nullis 
staminibus 4-5 nunc 8 (ex Don).—Spirea barbata, Wall. Cat. s Camb. 
Jacquem. bot. p. 48, t. 58. ex Decaisne, 
Hab in montibus Nepali, 
2. A.decandra (Don); floribus dicecio-polygamis, calyce 5-partito uno ovano 
tantum adnato, petalis anguste lineari-spathulatis (in pl. fert. subnullis) 
staminibus 10 (in pl. fert. abortivis).—Spirza Aruncus var. hermaphrodita, 
Michaux. Tiarella biternata, Vent, hort. Malmais. t, 34, Astilbe decan- 
dra, Don ; Torr, et Gray. fl. N. Amer. 1. p. 589. Hoteia biternata, 
caisne, in Ann. Sc. Nat. (ser. 2,) t. 11. f. 11. et 12. et 7. p. 36. 
Hab. in montibus Carolinz et Tennessee. ; 
3. A. Japonica, floribus hermaphroditis, calycis profunde quinque-f 
tubo basi ovarii adnato, petalis oblongo-spathulatis, staminibus 10- 
Spiræa Aruncus, Thunb. fl. Japon. p. 211, non Lima, S, barbata, 
Bot. Reg. t. 2011, non Wall, Hoteia Japonica, Morr, et Decaisne, in 4 
Sci. Nat. (ser. 2.) et t. 11. et 7. p. 30. | 
Hab. in Japonica. 
RE 
