FIELDBOOK OF ILLINOIS WILD FLOWERS 
and contain a selection of the lesser groups—genera, species and 
a few varieties or subdivisions of species. 
All these division-units, or groups, have individual names, 
and no two family, order or genus names are alike. The technical 
name is in Latin or Greek, and most groups have a common 
name in English as well. Thus we have the Rosaceae or Rose 
family, containing the genus Crataegus or Hawthorns, of which 
one species, Crataegus mollis, will be found on page 149 as the 
red haw. Genus and species together comprise the scientific 
name of a plant, and this is followed by initials or abbreviations 
to indicate the person who is the authority responsible for the 
name. Latin and Greek are used because they are more generally 
understood and have been adopted for this use in many 
countries. 
In this book the technical names are, with a few exceptions 
in the nature of corrections, from Gray’s Manual of Botany, 
seventh edition, and the plants are listed by families in the 
order of that text. Common names have been chosen from a 
variety of sources, and in each case are those which seem to 
enjoy the greatest favor. But the important thing for us is to 
get acquainted with the wild flowers, make friends of them, and 
learn to call them by some accepted name. Whether we use 
Latin or English matters little so long as we understand which 
plants are meant. 
THE USE OF KEYS 
If our only means of identifying a wild flower were to hunt 
through descriptions of several hundred species, such as are in 
this book, the task would be difficult and tedious. If, however, 
we had a quick way of recognizing the family to which the 
plant belonged and then were told where in the book the family 
might be found, locating the plant would not be much trouble. 
To take the short-cut we consult a key. Step by step through 
a number of plant characteristics, such as “petals 5,” “petals 
4,” we will pick our way, selecting those bits of description that 
fit the plant we have found and rejecting those which do not, 
until we complete the series and arrive eventually at the family 
and page on which our specimen is discussed. 
Suppose that about June I we start on a hike and in passing 
through a rather open, gravelly woods we find a little plant 
with a cluster of basal leaves that remind us of clover, and a 
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