BOOK REVIEWS 



Pennell on Scrophulariaceae^ 



A few years ago the late Dr. B. L. Robinson regretted the 

 dearth of thorough and comprehensive monographic studies by 

 American botanists. In this work by Pennell we have a re- 

 markable contribution to this need, written with such sanity, 

 clarity, accuracy and completeness that it would certainly have 

 pleased Dr. Robinson with his well known zeal for detail and 

 precision. 



One needs only to read the introductory chapter of forty- 

 five pages to grasp the spirit of the author: originality, without 

 excessive manufacture of either species or varieties; modernism, 

 still with adherence to the traditions of the past; obedience to 

 nomenclatural rules, even though under mild protest; thorough- 

 ness, both in the field and the herbarium; and above all an 

 occasional admission of imperfectness in his knowledge which 

 deepens the confidence of the reader in the general accuracy of 

 the book. 



The day of old-fashioned taxonomy is past, at least for such 

 countries as the United States. External morphology, derived 

 from herbarium specimens alone, is no longer adequate evidence 

 of specific limitations and relations. Pennell supplements struc- 

 ture with extensive field experience and correlates his results 

 carefully with geographic distribution and fioral migrations. 



Obviously no critic is competent to discuss the merits of 

 Pennell 's concept of species and varieties unless he can rely on 

 a personal experience as broad and as deep as the author's. 

 I doubt if any such person exists. Certainly the keys, which 

 largely replace the conventional descriptions, convey a fine 

 impression of accuracy, of completeness and, especially, of 

 balance and uniformity. There is no impression of "splitting" 

 in one genus and of "lumping" in another. His species all seem 

 to be solid and substantial. They appear to be separated from 

 each other by characters of generally uniform weight. One feels 

 that each one really denotes a definite race of plants. 



Pennell 's idea of a species is eloquently discussed in his 



^ Pennell, Francis W.: The Scrophulariaceae of eastern temperate North 

 America. Monograph 1. Academy of Natural Sciences of Philadelphia, pp. 

 xiv -1-650. 155 maps, 43 figures. N. 27, 1935. $5.00. 



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