292 EDMUND W. SINNOTT AND IRVING W. BAILEY 



flowered Ranales and their allies are the most ancient members of 

 the phylum, but the distinction in all probabiHty belongs to one 

 of these two groups. The Amentiferae are almost exclusively 

 woody plants, as are the vast majority of the Ranales. 



Evidence that herbaceous angiosperms are of comparatively 

 recent origin is also presented by a study of famihes which possess 

 both woody and herbaceous members and in which it is possible 

 to determine, on floral or other evidence, the relative antiquity 

 of the two types. In the Leguminosae, for example, the Mimosoi- 

 deae and Caesalpineae are with very few exceptions trees or shrubs; 

 and the Papilionatae, which seem clearly to be more recent than 

 the other two groups, contain almost all the herbs in the family. 

 In a number of other orders and famihes (Umbelliflorae, Violaceae, 

 Polemoniaceae, Borraginaceae, etc.) and even in certain genera, 

 notably Potentilla, the same fact may be observed. In practically 

 every case where the phylogeny of a mixed group can be definitely 

 established it is found that the woody members are more ancient 

 in type than are the herbaceous ones. 



Still further evidence pointing to the same conclusion is fur- 

 nished by a general survey of the distribution of herbs among the 

 families of the dicotyledons. Of the 240 families belonging to this 

 group of plants hsted in Engler's Syllabus (7th ed.), 121, or a 

 trifle over 50 per cent, are entirely woody, whereas only 35, or 

 14 per cent, are entirely herbaceous. Eighty-four families, or 

 35 per cent, possess both woody and herbaceous forms. Of 

 these 14 are rarely herbaceous and 18 rarely woody. Of the 

 entirely herbaceous families, almost all are either parasitic, insec- 

 tivorous, or water plants, or are monotypic, and hence can lay no 

 strong claim to primitiveness. Practically all typical land herbs 

 belong to families which have woody members, as well; but many 

 more than half of the families possessing woody species (121 out of 

 205) include no herbaceous forms at all. Had the original type of 

 angiospermous vegetation been herbaceous, it would be very 

 improbable that over half of all the families should have lost 

 their herbaceous members. If woody plants are primitive, 

 however, we can easily see that herbs might have arisen in only 

 about half of the families. These facts are especially significant 



