2^ 
o 
Kaulfussia are occasional neighbors of the latter. Scattered throiigli 
the forest at lower altitudes are Aspidiuin (lifforme, A. dccurrens, Di- 
■plaziujri hulhiferurn and Pieris quadriaurita, beside the stron<^lv dimor- 
phous species, Psomiocarpa apiifoliu, Stenosemia aurita, S, Pinnatay and 
Lepforhilns latifolius, and the snbdimorphous i\^(^/j7troJf;/;>i diversUohum; 
and Lindsaya gracilis, Hyn^granuim nUsmfpfoUa, Diplazivm palluhim, J), 
tomentosum ( ?) and Pteris plurlcaudata, near the rain forest. The Inst 
is intermediate, sometimes growing with Diplazitun WilUamsi, 
Tlie dimorphism mentiojied above is, as far as it goes, a tropo2)hytic 
adaptation. Asplenium suhnormah and the little Ophlofjlofifi'nm growing 
on creek edges are more completely tropophytie, usually disappearing 
during the dry season. Unless Adimitum phdippensc is one, 1 round 
no specialized terrestrial tropophytes in the savanna-wood at San l?a?7ion. 
Elsewhere in the Islands, NothocJda'na deusa, CheiJanikes tenuifoJia and 
Jlchnintliostachys are parang plants active during tlie wet season only. 
The best defined society in this group of plants is that of the narrow 
ridges in the upper part of the high forest. These have a very limited 
flora, in which Callipferis cordifolla and especially Taenitis and Poly- 
stichnm aristafiirn are characteristic. SyngniDtina and Lindsaya gracilis 
are the only other ferns likely to be found here. 
The characteristic feature modifying all epiphytic vegetation is the 
limited and uncertain water supply. The structure and life of the plant 
are so profoundly altered in adaptation to this general feature, that 
details of the environment, especially those in regard to the moisture 
r 
present in the latter, are able to exert much less influence on either the 
structure or the distribution of epiphytes than on those of terrestrial 
ferns. Therefore, although many of the epiphytic ferns are confined 
to the canons and only a few have not been found in them, a division 
of the epiphytes along the lines adopted in treating the terrestrial species 
would encounter too many doubtful cases and would be supported by 
altogether too little difTerence in structure to be justifled. For the same 
reason, the epiplij tic vegetation of the high forest is more closely related 
to that higher up the mountain than is the terrestrial. 
Epiphytic plants are those growing essentially without contact with 
the soil. They are so called because they usually grow upon other ]>lants, 
but some flourish indilforently either in such a situation or on rocks, and 
a few grow as a rule, or it may be entirely, on cliffs or boM-lders. DavalUa 
pallida I found but once and then on stone. Such species might tech- 
r 
nically be called lithophytes or petropliytes, but such a distinction would 
express no important biological dift'erence. Species often or usually on 
rocks are NepJirolepls laurifolia, Asplenium vulcanicum, Antrophyiim 
semicosiatum (sometimes even terrestrial), Ilymenolepis spicata, Nipho- 
hoJus nummulayla'foJlus, Polypodlum revohdiim^ P. nigrescent, P. com- 
mutatam, P. alhldo-squamntum, Photinopteris speciosa, and the Dnrallia. 
alreadv cited. As rock-dwellers, these are practically confined to the 
