TEHON: FIELDBOOK OF NATIVE ILLINOIS SHRUBS 7 



spects. P^ull sentences are used throughout, and commonplace 

 words are employed wherever they can be made to fit accurately. 

 This, it is hoped, will make the text more easily read and will 

 give the botanically untrained user more vivid pictures of the 

 shrubs that are described. Measurements, given as inches or 

 fractions of an inch for small plant parts, are not so accurately 

 stated as would have been possible with the less-used metric 

 system, but the more familiar standard will be interpreted more 

 easily. 



It has not been possible to avoid technical words entirely. In 

 botany, as in every branch of knowledge, meaningful words re- 

 place circuitous expressions. Many of the technical words of 

 botany are adaptations of words in common use that express the 

 resemblance of plant parts to familiar objects. The number of 

 technical words with which one must be familiar is not large, 

 but there is a considerable number of terms that have special 

 meanings in the descriptions of particular shrubs. For the in- 

 terpretation of all these terms, a glossary is appended. 



Common and Scientific Names. — To the uninitiated, im- 

 posing scientific names may be confusing, as also may be the fact 

 that a single shrub is given two or three common names. 



Common names differ from locality to locality. A shrub 

 known in one place under one name may be known in another 

 place under a different name. It is true also, now more than 

 formerly, that in one locality a shrub may be known by a num- 

 ber of common names. It is therefore impossible to determine 

 what common name is proper. In this text, common names 

 known to be in use in Illinois are preferred to those used else- 

 where. 



To som.e extent scientific names prevent the confusion that 

 arises from common names. In principle, at least, there should 

 be only one scientific name for each kind of plant. This principle 

 does not work out perfectly in practice, but its convenience and 

 serviceability cannot be doubted. 



In general, the scientific nomenclature used here is that of the 

 Second Edition, published in June, 1940, of Alfred Rehder's 

 Manual of Cultivated Trees and Shrubs. But some deviation 

 has been necessary, since, at the time of the publication of 

 Rehder's Second Edition, this text had been completed for two 

 years, the illustrations for one year, in the form in which they 

 were to be presented. Genera are more freely segregated into 



