Fossil Flora from Pagan — FOSBERG AND CORWIN 
15 
Pagan or in the northern Marianas but com- 
mon on rough limestone on Guam. An asso- 
ciation of plants similar to that in which this 
species grows on Guam occurs on rough lava 
in the northern Marianas on Alamagan Is- 
land, which is much like Pagan. Something 
like this association may have existed on 
rough lava in pre-caldera time on Pagan. 
Sample PC-79 
Pteris quadriaurita, Pandanus tectorius, Frey- 
cinetia mariannensis , Miscanthus floridulus , Cocos 
nucifera , Trema argentea , ? *Macaranga thomp- 
sonii , ? Eurya nitida 
From the assemblage of plants represented 
here the habit could have been the margin of 
a mixed thicket, possibly second growth, 
bordering on swordgrass. The presence of a 
seedling coconut suggests the possibility of 
human disturbance. 
Sample PC-84 
Miscanthus floridulus 
The vegetation indicated is swordgrass. 
Sample PC-85 
? Freycinetia mariannensis , Miscanthus flori- 
dulus, *Dianella ensiformis 
Swordgrass vegetation close to either a 
thicket or a rock cliff, unless what are here 
identified as Freycinetia leaves are really Pan- 
danus, in which case it would have occurred 
as scattered trees or thickets in the swordgrass. 
Sample PC-86 
Pandanus tectorius , Miscanthus floridulus , Me- 
lanolepis multiglandulosa, Premna ohtusifolia 
Unidentified mold. 
Probably swordgrass with mixed thickets 
or patches of scrub forest of Pandanus and 
broad-leafed trees. 
Sample PT-7 
Hernandia sonora , Aglaia mariannensis , Elaeo- 
carpus joga, ? *Tristiropsis ohtusangula 
This association suggests a forest of the 
sort that grows on rough lava on such islands 
as Alamagan at the present day, or on rough 
limestone on the islands farther south. 
Sample ID2 (F) 
Pandanus tectorius , Miscanthus floridulus, 
*Dianella ensiformis, *Spatho glottis micronesiaca 
Unidentified leaf scar or fruit impression. 
The conditions suggested by this small 
flora are those of swordgrass, possibly some- 
what sparse, with either thickets or scattered 
trees of Pandanus. 
Sample ID3i 
Miscanthus floridulus 
Probably swordgrass vegetation. 
From the foregoing lists it will be seen that 
there is meager evidence for any comprehen- 
sive opinions on the past vegetation of Pagan. 
Most of the indications are that at least some 
of the vegetation was much the same as that 
found on the island today. Swordgrass occurs 
in all but the two lowest horizons, and there 
is little doubt that it dominated the vegeta- 
tion wherever there was a loose ash substra- 
tum. Undoubtedly there were scattered trees 
or clumps of Pandanus and probably mixed 
thickets and scrub forest of Pandanus and 
other trees. Although the coconut does not 
appear in most of the lists of species, it may 
very well have been present in all of the later 
horizons, as there is little doubt that it was 
introduced by the early Chamorros and no 
reason why it would not have persisted 
whether or not they inhabited the island for 
any great length of time. An interesting fact 
is the complete lack of Casuarina in the col- 
lections. Next to Miscanthus it is the most 
abundant component of the modern vegeta- 
tion of the island. It adds to the scanty evi- 
dence that Casuarina may be a recent arrival 
in the Marianas, but this is still an unsettled 
question. 
The two lowest horizons, with plants com- 
monly found on rough lava or rough lime- 
stone and with one tree not known today on 
Pagan, possibly represent a slightly more 
mature vegetation than any known at present 
on the island, though it may actually be rep- 
resented in the mixed forest type. Something 
like it is prominent on extensive rough lava 
