THE AAIERICAN BOTANIST 151 



have two-lobed leaves, are said to have been named for the 

 two Bauhin brothers, but which is Caspar and which is John 

 nobody seems to know. — Bd.] 



The Rarity of Conophous. — If I had to base my 

 opinion as to the frequency of Conopholis americana 

 on my own early experience, I should never have 

 been inclined to regard it as "rare." While not as abun- 

 dant as its near relative Bpifagus virginiana, and somewhat 

 more inclined to occur only in the neighborhood of oaks, it 

 was by no means an uncommon plant in the hilly woods along 

 the Ohio River in Boone County, Kentucky. One must never 

 base his judgment as to the rarity of a plant, however, on ob- 

 servations limited to a single locality. For example, Gray's 

 Manual refers to the teasel (Dipsacus sylvestris) as "rather 

 rare," which in the locality mentioned above, it was one of the 

 commonest and most pestiferous weeds. Particularly in the 

 case of introduced plants, all attempts to indicate distribution 

 over any but the most restricted area are likely to result in 

 acute inaccuracy. In fact, these words "rare," "common," 

 "frec[uent," etc., are very far from being capable of that 

 strict definition which is supposed to characterize scientific 

 terms. Mr. C. C. Deam, in the last edition of his Trees of 

 Indiana, has made a praiseworthy attempt to give precision to 

 such expressions by inventing a code based on the number of 

 individuals per acre ; but while it is possible to count the num- 

 ber of trees on an acre, such an undertaking in the case of 

 herbaceous plants would hardly be feasible. Perhaps except 

 in strictly local floras, it might be better to abandon the use 

 of such words entirely, and thus eliminate what must always 

 partake more or less of the "personal equation." — /. C. Nel- 

 son, Salem, Oregon. [It must be remembered, however,, that 

 a plant may be rare in a region because suitable conditions for 

 growth are rare. Now that we know more about plant asso- 



