48 PITTONIA. 
P.cawEscENS. Lippia canescens, HBK. l1. c. Widely dis- 
persed in tropical and subtropical South America, inhabit- 
ing grassy plains; the leaves much larger than in the pre- 
ceding, not in the least plicate, but quite plane. 7 
P. BETULÆFOLIA. Lippia betulefolia, HBK. 1. c. 264. In- 
digenous to northern South America; marked by larger 
leaves of rhombic-ovate outline, with impressed pinnate 
veins, and coarse sharpserrate teeth. Though strictly of this 
genus, Mr. Bentham is said to have made it the type of a 
new one, Cryptocalyx nepetxfolia, see DC., Prodr. xi. 584. 
SIEVERSIA. 
Willdenow, Berl. Mag. v. 397 (1811); R. Br. in Parry's 
First Voyage, App. 276 (1824); G. Don, Gen. Syst. ii. 527 
(1832). Species of Gewm with most earlier and later authors. 
The essential characters of Sieversia as distinguished from 
Geum are those of its style; this organ here being slender, 
straight, continuous without articulation or bend, and in 
fruit wholly persistent and plumose; whereas in Geum it is 
short, stiff, jointed and bent at or near the middle, the upper 
portion eventually falling away. It is therefore a more 
strongly fortified genus than is Pulsatilla as compared with 
Anemone ; for in this instance the style in neither genus is 
either bent or jointed or in any part deciduous; and Pulsa- 
tilla rests on no other character of fruit than its elongated 
and slender plumose styles. It is habitally somewhat un- 
like Anemone, yet not more so than Sieversia is unlike Geum ; 
so that, on the whole, Sieversia is a better genus than Pulsa- 
tilla; and there have not been wanting eminent botanists 
who maintained the former while declining to give reeogni- 
tion to Pulsatilla, as for example Sir William Hooker in the 
Flora Boreali-Americana ; George Don in the General System, 
and Endlicher, Genera Plantarum ; and there are others; 
while the extreme of inconsistency is chargeable to some re- 
cent authors who maintain Pulsatilla yet suppress Sieversia. 
