6 
MERRILL. 
noted above that about 26 species of this family, found in the Philippines, 
are of American origin; it is worthy of note that but 5 of these have 
been found in Polillo. The fact that there are so few of these American 
plants definitely known from Polillo, leads us to conclude also that many 
of the other species, now cosmopolitan in the tropics, abundant in other 
parts of the Philippines, but wanting in Polillo, have been introduced 
into the Archipelago in comparatively recent times, perhaps contem- 
poraneously with the introduction of many of the American species, and 
like the latter have not as yet reached the isolated parts of the Archi- 
pelago. 
Some cases of geographical distribution are worthy of note, but evi- 
dence of special affinities with the flora of surrounding regions is not as 
strong in this family as it is in some others. The flora as a whole is 
preponderatingly Malayan. Excluding from the present consideration 
the species that manifestly have been introduced from tropical America, 
and are now for most part widely distributed in Indo-Malaya, we have 
about 150 common to the Philippines and the Malayan region; of these 
about 120 are common to India, the Philippines, and Malaya, and many 
also extend to other regions. About 31 are confined to the Philippines 
and Malaya, but less than one-half this number are common to con- 
tinental Asia and the Philippines and do not extend to Malaya. 
The following species extend from northern India to China and the 
Philippines: Desmodium podocarpum DC. (also in Japan), D. retro- 
flexum DC., Indigofera nigrescens Kurz, Lespedeza juncea var. sericea 
Forbes & Hemsl. (also in Australia), Shuteria vestita W, & A., and 
Smithia ciliata Eoyle. Prom northern India and the Philippines, but 
not reported from China, we have: Doliclnos falcatus Klein, Crotalaria 
acicularis Ham. (also in Java), Desmodium pseudotriquetrum DC., and 
Crotalaria assamica, while the genus Eingiodendron has one species in 
India, and one in the Philippines. Confined to China and the Philip- 
pines we have PTiaseolus minimus Roxb., while Gleditsia rolfei Vid., 
Luzon and Celebes, and the only representative of the genus in Malaya, 
is closely allied to species of southern China, the genus not being repre- 
sented in India except by introduced species. A considerable number of 
the above continental types are confined to the Benguet-Lepanto region 
in northern Luzon, in the regional distribution of Pinus insularis Endl., 
but others are widely distributed at low altitudes. Acacia confusa Merr., 
which has been identified by some authors with A. richii A. Cray, of 
Polynesia, is the only species, known to me, common and confined to 
Luzon and Formosa; however, this species must be considered an Aus- 
tralian type as it is one of the few extra-Australian species of the great 
group PTiyllodineae so characteristic of that continent. Desmodium 
duergeri Miq., a Japanese species now reported from the Philippines, 
has been confused with D. heterocarpum (L.) DC., so that its exact 
range is uncertain. 
