Ferns of British India and Ceylon. 187 
18. DiPLAZiUM i.ATiFOiJUM. {Boji.) Like polypodioides, 
only the secondary pinnae are generally much less cut down, and 
often much broader, they are sometimes almost entire, or with only 
shallow serratures, when the fern has quite the appearance of 
" sylvaticum," only bipinnate instead of simply pinnate ; other forms 
have the secondary pinnae 2 inches (or even more) broad at the 
base, cut down a third or half-way to the rachis ; segments always 
more or less crenateor serrate; veinlets simple or forked, rather dis- 
tant, their number depending on the size of the segments (never so 
numerous as in asperum, except when the segments are double 
the size of those of that plant) ; sori narrow, often occupying the^ 
whole length of the veinlet, and reaching the margin ; indusium some- 
times obsolete or early caducous. Do?!. Prod. Fl. Nep. 8. Hook. 
Syn. Fil. 239. Dip. dilatatum, Zr^?^'/C'. Sp. Fil. iii. 258. Bedd.F. S. I. 
162, a form running nearer polypodioides. Dip. maximum, Hook. 
Syn. Fil. 232, in part. 
Madras Presidency, in aU the Western forests. North 
India, throughout the Himalayas and Khasya Hills. Ceylon ; 
Malay Peninsula ; from very low altitudes up to 9,000 feet 
elevation. 
(Also in Australia, China and the Philippines.) 
If we only included here species with very broad secondary 
pinnae, not cut more than half-way down to the rachis, this 
plant would be very distinct from " polypodioides," but I fear this is 
not possible, and in all large herbaria, I find specimens that it is 
very difficult to say which species they should be referred to. 
Diplazium torrentium and succulentum of Clarke cannot be made 
into distinct species, unless we also make many more, but they 
belong to types which, though generally referred here, must, from the 
deeper cutting of their secondary pinnae, go into " polypodioides," if 
the two are to be kept distinct ; no figures and no description could 
enable any one to distinguish some of these forms as species, the 
only difference often being the extent of the cutting of the secondary 
pinnae. D. decurrens unless a distinct species (which view its 
venation I think supports), should rather be referred here than 
