190 
MERRILL. 
Table II . — Summary of species, etc. — Continued. 
Families, genera, and species. 
Natural distribu- 
tion. 
Purposely intro- 
duced. 
I Accidentally in- 
troduced. 
Cultivated. 
j Spontaneous. 
American origin. 
1 Oriental or Euro- | 
1 pean origin. | 
Origin doubtful 
or unknown. 
COMPOSITAE: 
Eupatorium triplinerve Vahl. _ 
X 
X 
X 
Ageratum conyzoides L. 
X 
X 
X 
Emilia sonchifolia DC. 
X 
X 
X? 
Elephantopus scaber L. . 
X 
X 
X 
Elephantopus mollis HBK. - _ 
X 
X 
X 
Elephantopus spicatus Aubl. __ _ ^ 
X 
X 
X 
SynedrellanodifloraGaertn. 
X 
X 
X 
Artemisia vulgaris L. 
X 
X 
X 
Rrityeron linifnlins Willd 
X 
X 
X 
Taffetea eroota Ti. 
X 
X 
X 
Rr»lirifn aIHs) 
X 
X 
X 
Helianthna annnna T.. 
X 
X 
X 
PlnQTTiAQ pniiHatna TTPtTT 
X 
X 
X 
Bidens pilosa L. _ 
X 
X 
X 
Lactuca sativa L. _ 
X 
X 
X 
Sonchus oleraceus L. -- 
X 
X 
X 
Chrysanthemum indicum L. 
X 
X 
X 
Totals 
90 
242 
92 
197 
227 
177 
138 
109 
Very many of our species are to be found in practically all 
tropical countries in both hemispheres; in fact, of the 1007 
included in the Manila flora, about 425 are now found in tropical 
America and in the tropics of the Orient, although not all of these 
are of general distribution. Some of these are manifestly of 
natural distribution, but the greater number have unquestion- 
ably been distributed by man, either purposely or accidentally, 
and within the past 390 years. I consider it very probable that 
not more than 92 of the 425 pantropic species under considera- 
tion are of natural distribution, that is, those species that have 
extended to the tropics of both hemispheres, and sometimes 
also to more temperate regions, without the direct or indirect aid 
of man. In at least one-half of these 92 cases which I have 
considered as presumably of natural distribution, there is a 
reasonable doubt as to whether they may not have been distri- 
buted from one hemisphere to the other by man. 
Among the species that are unquestionably of natural distri- 
bution in the tropics of both hemispheres may be mentioned the 
following: Dryopteris parasitica 0. Ktze., Nephrolepis cordi- 
folia Presl, N. hirsutnla Presl, Adiantum philippense L., A. cauda- 
tum L., Pteris longifolia L., P. quadriaurita Retz., P. biaurita L., 
