5 
Sinnott and Bailey . — The Origin and 
It is a noteworthy fact that in practically every instance where there 
are herbs and woody plants in the same group, and where it is possible to 
determine from floral evidence their relative antiquity, it is found that the 
woody plants are more primitive than the herbaceous ones. This is inex- 
plicable on the theory which regards the herb as the most ancient type of 
Angiosperm vegetation, but is much easier to understand on the alternative 
hypothesis. 
Still further evidence, as to the relative antiquity of the two plant-types 
under consideration, is furnished by a general survey of the distribution of 
herbs among the families of the Dicotyledons. Of the 240 families enu- 
merated in Engler’s ‘ Syllabus* (7th edition), 121, or just over 50 per cent., 
are entirely woody, whereas only 35, or 14 per cent., are entirely herbaceous. 
84 families, or 35 per cent., possess both woody and herbaceous forms; of 
these 14 are rarely herbaceous and 18 rarely woody. The 35 entirely 
herbaceous families are the following : Saururaceae, Balanophoraceae, 
Rafflesiaceae, Hydnoraceae, Cynocrambaceae, Basellaceae, Nymphaeaceae, 
Ceratophyllaceae, Tovariaceae, Resedaceae, Sarraceniaceae, Nepenthaceae, 
Droseraceae, Podostemonaceae, Hydrostachyaceae, Cephalotaceae, Tro- 
paeolaceae, Callitricaceae, Limnanthaceae, Stackhousiaceae, Balsaminaceae, 
Hippuridaceae, Cynomoriaceae, Pirolaceae, Lennoaceae, Primulaceae, Peda- 
liaceae, Martyniaceae, Orobanchaceae, Lentibulariaceae, Globulariaceae, 
Phrymaceae, Adoxaceae, Brunoniaceae, and Calyceraceae. It is evident 
that almost all of these families are either parasites, insectivorous plants, 
water plants, or are monotypic, and that they can lay no particular 
claim to being primitive. Practically all the typical land herbs belong to 
families which have woody members as well, but much more than half of 
the families which have woody plants (121 out of 205) possess no herbaceous 
forms at all. 
It is hard to explain such a fact as this on the hypothesis that herbs 
are extremely ancient, for if they were there would naturally be many more 
entirely herbaceous families, and it would be very improbable that over 
half of all the families should have lost, or at least should be without, 
herbaceous forms. If we believe that practically all land families originated 
as woody plants, however, and that the herbaceous type was developed 
independently in a little less than half of the families, we can understand 
the facts much more clearly. 
A study of the distribution of the two types in the Archichlamydeae 
and in the Metachlamydeae is also of interest. Of the 3 , 55 I genera 
enumerated by Engler in the former great group, 2,397 are woody, or 
68 per cent., and only 1,154, or 32 per cent, are herbaceous. Among the 
3,002 genera in the Metachlamydeae, however, only 1,254, or 42 per cent., 
are woody, considerably more than half being herbaceous. Trees constitute 
53 per cent, of the woody Archichlamydeae, but only 23 per cent, of the 
