SEQUOIA AND ITS HISTORY. 155 



peculiar genera of one family, each of a single species in the 

 Atlantic United States, which are duplicated on the other 

 side of the world, either in identical species, or in an analo- 

 gous species, while nothing else of the kind is known in any- 

 other part of the world. 



I ought not to omit Ginseng, the root so prized by the 

 Chinese, which they obtained from their northern provinces 

 and Mandchuria, and which is now known to inhabit Corea 

 and northern Japan. The Jesuit Fathers identified the plant 

 in Canada and the Atlantic States, brought over the Chinese 

 name by which we know it, and established the trade in it, 

 which was for many years most profitable. The exportation 

 of Ginseng to China probably has not yet entirely ceased. 

 Whether the Asiatic and the Atlantic American Ginsengs 

 are to be regarded as of the same species or not is somewhat 

 uncertain, but they are hardly, if at all, distinguishable. 



There is a shrub, Elliottia, which is so rare and local that 

 it is known only at two stations on the Savannah River, in 

 Georgia. It is of peculiar structure, and was without near 

 relative until one was lately discovered in Japan (Tripeta- 

 leia), so like it as hardly to be distinguishable except by hav- 

 ing the parts of the blossom in threes instead of fours, — a 

 difference which is not uncommon in the same genus, or even 

 in the same species. 



Suppose Elliottia had happened to be collected only once, 

 a good while ago, and all knowledge of the limited and obscure 

 locality were lost ; and meanwhile the Japanese form came to 

 be known. Such a case would be parallel with an actual one. 

 A specimen of a peculiar plant (Shortia galacifolia) was 

 detected in the herbarium of the elder Michaux, who collected 

 it (as his autograph ticket shows) somewhere in the high 

 Alleghany Mountains, more than eighty years ago. No one 

 has seen the living plant since or knows where to find it, if 

 haply it still flourishes in some secluded spot. At length it 

 is found in Japan ; and I had the satisfaction of making the 

 identification. 1 One other relative is also known in Japan ; 

 and another, still unpublished, has just been detected in 

 Thibet. 

 1 " Amer. Jour. Science," 1867, p. 402; "Proc. Amer. Acad.," viii. p. 244. 



