CHAPTER IX 

 THE CROWFOOT FAMILY 



101. General features. In several respects the crowfoot 

 family is the best one with which to begin our study of plant 

 groups. It forms an especially serviceable standard of com- 

 parison because its members, as Ave shall see, are remarkably 

 simple in their plan of structure — at least for seed-plants — 

 and at the same time the various species display a wide range 

 of variety in detail. Moreover, it was his careful study of 

 this family w^hich led the younger Jussieu to an understanding 

 of those fundamental principles of classification which he 

 applied so brilliantly in founding the natural system. To us 

 it will present problems which once solved will simplify and 

 illuminate all our future study. 



Of the plants already examinetl the following, as we have 

 seen, are of this family: marsh-marigold (Caltha palustris, 

 page 198), tall buttercup (Ranunculus acris, page 216), 

 cUtch crowfoot (R. sceleratus, page 216), wind-flower (Ane- 

 mone nemerosa, page 205), and monkshood (Aconitum 

 Napellus, page 191). The family is made up of about 700 

 species in about 30 genera. From the few examples above 

 given and a study of those shown in Figs. 282-297, we may 

 gain, however, a fair idea of the range of peculiarities exhib- 

 ited by the family as a whole. At first sight it may seem 

 scarcely possible to find among plants which differ so much 

 one from another any peculiarity or set of peculiarities 

 common to all and yet not possessed by other seed-plants. 

 Examination will show us, however, that as a group they 

 may be distinguished at least by the lack of complicating 

 features which other families show, and we shall find further- 

 more a few positive peculiarities which are more or less 

 characteristic. 



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