Rhodora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 20. February, 1918. No. 230. 
NOTES ON THE CLAYTON HERBARIUM. 
S.. FF. BLagE. 
OnE of the earliest works on the flora of the United States was 
Gronovius’s Flora Virginica, the first edition of which was published 
at Leyden in two parts in 1739 and 1743, the second in 1763. Worked 
out at Leyden with Linnaeus’s assistance in the 1730’s, from the series 
of specimens sent to Gronovius by John Clayton,! clerk of Gloucester 
County, Virginia, it is of extreme importance as affording the chief 
basis of perhaps the greater number of North American plants pub- 
lished in the Species Plantarum. Although Clayton’s herbarium, 
now incorporated in the general collection of the British Museum, has 
been frequently consulted by American workers, especially by Dr. 
Gray, no systematic examination of the whole collection appears to 
have been made, at least in recent years. While working at the British 
Museum in 1914 and 1915 I had an opportunity through the kindness 
of Dr. A. B. Rendle of making a careful study of the whole collection, 
and the rather numerous changes in nomenclature necessitated by the 
_ reidentification of Clayton’s specimens are here brought together. 
The interpretation of Linnaean names based on several prelinnaean 
references representing more than one modern species has always 
been a matter of difficulty, and has often led to serious differences of 
opinion. The uncertainty often attending the attempt to unravel 
the confused tangle presented by the Linnaean synonymy has in some 
cases led authors to cut the Gordian knot by arbitrarily typifying the 
Linnaean species by the specimens in the Linnaean Herbarium. It 
1 See Britten, Journ. Bot. xlvii. 297-301 (1909), for an interesting account of Clayton. 
