1918] Blake,— Notes on the Clayton Herbarium 49 
of Bartlett’s revision; the Plukenetian synonym is unidentifiable. 
It should be borne in mind that Clayton’s plants were worked out 
by Gronovius with the constant assistance of Linnaeus and that cita- 
tions from the Flora Virginica have therefore, as represented by still 
extant specimens actually seen by Linnaeus, a greater value today in 
the interpretation of Linnaean species than the often unintelligible 
descriptions and figures of earlier writers not now authenticated by 
specimens. The usual identity of citations of older authors in both 
the Flora Virginica and the Species Plantarum is also significant in 
this connection and may be taken as indicating the probability that 
the synonymy of the earlier work was likewise due to the coöperation 
of Gronovius and Linnaeus, and was later adopted directly by Lin- 
naeus for the Species Plantarum. In any case, the fact that the 
Flora Virginica is nearly always the first cited and that its species are 
still represented by a nearly complete suite of specimens, while those 
of the older authors have in most cases to be determined ‘on the basis 
of more or less dubious figures and descriptions, makes it of supreme 
importance in the determination of Linnaean names based on com- 
plexes of the sort exemplified in Dioscorea villosa, It seems to the 
writer that D. vittosa L. must be retained, as it was by nearly all 
the early American authors, and based on Gronovius’s Dioscorea foliis 
cordatis acuminatis &c., which rests on Clayton 94, the Plukenetian 
synonym being excluded, and Michaux’s D. paniculata, published as a 
mere renaming of the Linnaean species, referred to its synonymy. 
The glabrous-leaved variety, D. paniculata var. glabrifolia Bartlett, 
l. c. 15 (1910), recorded from Connecticut to Kansas and Texas by 
Bartlett, and later from southwestern Michigan by E. J. Hill (Rao- 
DORA xiii. 35 (1911)), becomes D. vrutosa L. var. glabrifolia 
(Bartlett). 
5. Lechea major L. Sp. i. 90 (1753)! — Helianthemum majus (L.) 
BSP. Prel. Cat. 6 (1888), in part.— The type of this species, collected 
by Clayton (“in Collibus arenosis promontorii Point Comfort dicti 
Comit: Glocestiae”), is the same species as Cistus canadensis L. Sp. 
i 526 (1753),2 the Helianthemum canadense of Michaux, FI. i. 308 
1 Lechea major. 
“9 LECHEA foliis ovati-lanceolatis, floribus lateralibus vagis. Gen. nov. 1074. f. 4.* 
“ Habitat in Canadae aridis.” 
2 Cistus canadensis. 
“17. CISTUS herbaceus exstipulatus, foliis omnibus alternis lanceolatis, caule adscendente. 
“ Habitat in Canada. Kalm. 
“Facies C. Helianthemi, sed Folia alterna.” 
