THE FLORA OF MANILA. 
175 
the first description of Pithecolobium dulce Benth. (as Mimosa 
dulcis) , from specimens grown in India, but definitely states 
that it was introduced from the Philippine Islands, his inference 
being that it was a native of this Archipelago. However, the 
species is of wide distribution in tropical America, and although 
no definite record as to the date of its introduction into the Philip- 
pines has been found, still we know from its usual habitat here 
and from its native names that it is not an indigenous plant. It is 
locally kown as camanchile, camonsil, camatchile, and variations 
of these names, manifestly corruptions of its old Mexican name, 
quamochitl, the name having been introduced by the Spaniards 
with the plant. 
The genus Rotala of the Lythraceae contains about 38 species, 
and has representatives in most warm countries, some confined 
to one hemisphere, some to the other. Rotala imnosior (L.) 
Koehne extends from the northern United States southward 
through Mexico and Central America to Brazil, and is also of 
wide distribution in the Philippines, occurring here as a rice- 
paddy weed. It is unknown from any other part of the Orient. 
It is certainly not an indigenous species with us, and undoubtedly 
was accidentally introduced at an early date through the medium 
of the Acapulco-Manila galleons, and finding favorable local con- 
ditions, became established. 
Elephantopiis, a genus of the Compositae, has about 16 species, 
mostly confined to tropical America, but we have in the Philip- 
pines three manifestly introduced ones. One of these, E. scaber 
L., is now distributed to most tropical countries, but E. spicatus 
Aubl. and E. mollis HBK. are unknown outside of tropical Amer- 
ica, except in the Philippines and Guam; in the Philippines all 
three are common and widely distributed. Unquestionably they 
have all been introduced from tropical America, and through the 
medium of the Acapulco-Manila galleons. 
Acacia farnesiana Willd. is a species of very wide distribution 
in tropical and subtropical countries, and most authors are con- 
tent with indicating its range as cosmopolitan in the tropics 
without attempting to determine its origin. In some countries 
it is thoroughly naturalized and is very abundant, as in some 
parts of the Philippines, while in others it is cultivated only. It 
was originally described from American material and there is 
every reason to believe that it is of American origin, and that it 
has been purposely distributed for the sake of its fragrant flowers. 
In the Philippines it is now never cultivated, and is so very 
