188 Rhodora [OCTOBER 
This is the very specimen upon which the additional note given 
above is based. This note was written by Linnaeus himself when he 
(at that time living in Holland) and his bosom friend Gronov 
elaborated Clayton’s notes on the flora of Virginia prior to 1739. 
For this reason the Claytonian plant which Linnaeus himself knew 
has the only claim to the name Pinus canadensis. Since the Linnaean 
description is definitively that of the hemlock while the Linnaean 
citations are a mixture of names referring to the two species (Tsuga 
canadensis and Picea canadensis) the former is the only clear element 
in the concept of the Linnaean species and should determine the 
application of the Linnaean name. Under the circumstances it 
seems “unfortunate,” not that Linnaeus placed the reference to the 
Flora Virginica under a specific description drawn up almost verbatim 
from the Gronovian name cited under it, but that he included in his 
species the plant of Miller which in the three features distinctive of the 
hemlock spruce (“foliis linearibus obtusiusculis submembranaceis”’ ) 
is utterly at variance with the description given by Linnaeus of his 
Pinus canadensis — i. e., Tsuga canadensis (L.) Carr. 
Bureau or Prant Inpustry, Washington. D. C.’ 
A MANUAL oF THE Grasses oF ILLINoIs!— This manual gives 
descriptions of 63 genera and 204 species with keys to the genera and 
to the species. An introductory account of the structure of grasses 
includes the morphology necessary for the student who wishes to 
undertake the study of the family. Each species is illustrated by a 
figure of the spikelet and a few by a figure of the inflorescence or by a 
habit sketch of the entire plant. The drawings are somewhat im- 
pressionistic but nevertheless will be very helpful to the student. 
The work is based upon a study of specimens and is not a compila- 
tion, a fact which differentiates this from several other articles dealing 
with local grass-floras. The descriptions are as untechnical as con- 
sistent with precision. The keys are artificial but thereby more 
usable by the amateur for whom the book is intended. 
Appended to the descriptions of the species are notes on habitat, 
distribution, and economic value, and a detailed list of specimens. 
The author studied the important local collections including that 
at the Field Museum, and also visited the National Herbarium. The 
work shows every evidence of careful investigation and in both form 
and substance is a model for a local flora.— A. S. Hircucock, Wash- 
ington, D. C, 
1 The Grasses of Illinois by Edna Mosher. Ill. Agr. Exp. Sta. Bull. 205: 261-425. 1918. 
Vol. 20, no. 237, including pages 153 to 172, was issued 4 September, 1918. 
