1911] Book Review 35 
The latter mainly considers the rhizome of Dioscorea, the part used 
in pharmacy. It is well illustrated by figures that will prove of value 
also in identifying the plants by the subterranean portions of their 
stems. The former is a monograph of the Dioscoreae of the United 
States as viewed and elaborated by Mr. Bartlett. It is well known 
that but one species, D. villosa L.,is given in all recent books treating 
the flora of this area. Bartlett makes five, three with names which 
had been used by previous authors, with two new species and one new 
variety. From maps that accompany the text showing the distri- 
bution of the three with revived names it is seen that they come into 
the “Manual region." They are (1) D. paniculata Michx., the most 
widely distributed species, from southern New England to eastern 
Kansas and Oklahoma, but most abundant in the north central 
States; (2) D. glauca Muhl., from Pennsylvania through the two 
Virginias, Kentucky and southward, but “being essentially a plant 
of the mountains” it is mainly found along the Appalachian belt; 
(3) D. quaternata (Walt.) Gmel., principally southern, coming into 
the “Manual region” in western Kentucky and eastern Missouri. 
D. paniculata var. glabrifolia Bartlett mostly replaces the typical 
form in the southwestern part of its range but is represented in Con- 
necticut, Pennsylvania, Maryland and Missouri. The writer has a 
fruiting specimen of D. paniculata from southwestern Michigan that 
from the description would go with the variety, being perfectly smooth. 
The two new species, D. hirticaulis Bartlett and D. floridana Bartlett 
are southern species of the Atlantic coastal plain. 
It will be seen from this that D. villosa L. does not appear in this 
list. The reason given by Mr. Bartlett for dropping it is that pro- 
vision of the Vienna code which allows a name to be discontinued 
“when the group which it designates embraces elements altogether 
incoherent, or which become a permanent source of confusion and 
error.” The only basis for a type, if such it could be called, found 
in the herbarium of Linnaeus, is a sheet with an American plant; 
“at the bottom of which,” according to Dr. B. Dayton Jackson, 
Secretary of the Linnaean Society, “is a note by Linné himself, 
‘6 K sativa,’ to which Smith has added in pencil, ‘non est.” No 
specimen named “villosa” by Linnaeus was found by Dr. Jackson 
in the herbarium. D. sativa L. is an East Indian plant, and since the 
sheet is marked as collected by Kalm (“K = Kalm”) but named 
sativa, there is evidently a mistake or a confusing of Asiatic and Ameri- 
can species, since Kalm collected in America. A. De Candolle found 
a similar confusing of species of Dioscorea by Linnaeus when he con- 
sidered the origin of cultivated plants in his “Géographie Botanique,” 
and more fully treated in a later work “L’Origine des plantes cul- 
tivées.”! Under the name D. sativa Linnaeus had confounded sev- 
eral Asiatic and American species. Grisebach, in his “Flora of the 
1 ], c. p. 62. 
