108 Evans: TAXILEJEUNEA PTEROGONIA 
The female inflorescence, for example, may be borne on a long 
branch with large leaves, or the innovation of the first inflorescence 
formed may be sterile. In such cases the systematic position 
may be one of great uncertainty. 
The bracts in Taxilejeunea tend to be smaller and narrower 
than the stem leaves, and the lobules, which are always much 
smaller than the lobes, are often reduced to vague basal folds, 
which are scarcely apparent when the bracts are spread out flat. 
In other cases the apices of the bracts are distinct, and much 
variation is sometimes found even in a single species. The 
bifid bracteoles are usually broader than the bracts and often 
equal them in length. The perianths exhibit great diversity in 
the different species and considerable variation in a single species 
is sometimes encountered. The lower part is almost always 
terete, and this condition may extend throughout the length of 
the organ, being evident even in the inflated apical portion. In 
other cases the perianth is five-keeled, the keels extending to 
below the middle or restricted to the upper part. The keels, in 
turn, may be smooth or variously toothed and winged. In old 
and battered perianths the true features are sometimes greatly 
obscured. 
The species discussed in the present paper are all typical 
members of the genus. They all show leaves which are cordate 
or auriculate at the base, more or less sharp-pointed at the apex, 
crenulate throughout and often vaguely toothed in the apical 
portion; and their underleaves are large, cordate or auriculate 
at the base and shortly bifid. They are all further distinguished 
by their sharply five-keeled perianths, the keels in the first three 
being more or less distinctly winged and toothed. In the fourth 
species, which is clearly a close ally of the others, the keels are 
smooth or vaguely crenulate. 
I. TAXILETEUNEA PTEROGONIA (Lehm. & Lindenb.) Schiffn. 
Jungermannia pterogonia Lehm. & Lindenb. in Lehmann, Pug. 
Plant. 6: 44. 1834. | 
_Omphalanthus pterogonius Lehm. & Lindenb. in G. L. & N. Syn. 
_ _Hep. 306. 1845. 
_ Omphalanthus subalatus Lindenb. & Gottsche in G. L. & N. Syn. 
- Hep. 747. 1847. 
Pa 
