120 T O R R E Y A 



cannot be expected to check every one ; indeed, many can never be checked 

 because the actual specimens on which they were based are not preserved ! 

 Painstakingly assembled state floras are urgently needed for each state in the 

 Union. Such state floras should contain an outline map of the state for each 

 species and variety discussed and should show the distribution of that plant 

 within the state by counties — as Deam's monumental "Flora of Indiana" 

 (1940) and Gates' "Flora of Kansas" (1940) do. Only after such an exhaus- 

 tive flora has been published for each state will workers on special groups of 

 plants be able to make accurate distributional maps for the country as a whole. 

 Compilers of such state floras — and the compilation of parts of such a state 

 flora could easily be made the subject of masters' and even doctorate theses in 

 state universities — should not only do extensive collecting in every county 

 of the state, but should have the benefit of published lists of the collections of 

 other botanists in that state, each such list having every record backed by an 

 actual specimen preserved in a readily accessible herbarium where it will be 

 available for checking by the compiler. 



Nearly all the species in Muenscher's book are illustrated by excellent line 

 drawings and there are many supplementary illustrations depicting differences 

 in leaf-venation of species apt to be confused with one another, enlargements 

 of fruits., etc. A unique feature of the book is the illustration of the seedlings of 

 almost every species. This is a splendid innovation and entirely in line with the 

 growing tendency among field botanists to learn to recognize members of the 

 flora in stages of growth other than the flowering and fruiting condition. Her- 

 barium and museum workers soon learn that a vast proportion of the speci- 

 mens brought or sent in to them for identification by amateurs, ecologists, 

 plant pathologists, anthropologists, and travellers, are "sterile," i.e., do not 

 bear the characteristic flowers and fruits. Botanists therefore have to learn to 

 recognize species by their vegetative characters — sometimes even by their 

 roots, in their dried or shriveled-up winter condition, or from miserably small 

 fragments. Herbaria ought to preserve representative specimens of each species 

 at every stage of its growth in order to assist workers in identifying such 

 "sterile" material. Muenscher's study of the seedlings of all the plants dis- 

 cussed is an admirable step in this direction. More such studies are needed and 

 more specimens of the various species in this and the various other pre- and 

 post-flowering conditions are needed in herbaria ! 



Notes, based upon field observations, are given by Muenscher on the vari- 

 ability, special habitat requirements, special uses, and other features of many 

 species. Differences in interpretation of various genera and species by different 

 botanists are occasionally giyen. It is to be regretted that they are not given 

 more uniformly. Common names are recorded for some, but not by any means 



