— 6i — 
of underleaves. Schiffner also was impressed by the features of the perianth, 
although he still retained Chascostoma (with a question mark) among the sub- 
genera of Nardia. 1 
In Figs. 1-3 more or less characteristic perianths are shown and in Figs. 6 
and 7 the upper parts of two other perianths are represented, dissected off and 
spread out flat. The figures indicate that the perianth is a somewhat variable 
organ. In most cases the apical lobes or laciniae are irregular in number, size 
and shape. They tend to flare out a good deal and are frequently revolute, 
but sometimes they are suberect or even involute, thus partially closing the 
mouth. In many cases the perianths are incompletely or abnormally formed. 
A lobe, for example, instead of meeting the next lobe directly, may extend down 
the outer surface of the perianth for a considerable distance in the form of a 
free lamella. Austin described the margins of the laciniae as entire. As a mat- 
ter of fact the marginal cells usually project as vague crenulations, and some- 
times minute and irregular teeth are present. The cells of the perianth vary 
considerably, although elongated cells are usually present somewhere. Even 
at the mouth the cells are often isodiametric, an unusual condition in the genus 
Nardia, but this feature is inconstant and the marginal cells are sometimes elong- 
ated. In the writer’s opinion the features of the perianth in N. fossombronoides 
have perhaps been over-estimated as a sectional or subgeneric character, but 
they certainly form an excellent basis for separating the species from its allies. 
Passing now to the vegetative organs the resemblance between N. fossom- 
bronioides and the northern N. obovata (Nees) Lindb. is striking. The plants 
are of about the same size, they are both distinguished by the presence of purple 
rhizoids and long stolons, the branching in both is intercalary, and both (so 
far as observed) show a complete lack of subfloral innovations. The leaves, 
moreover, are of about the same shape and spread in about the same way, while 
the leaf-cells are characterized by small but distinct trigones. Even the meas- 
urements of the leaf-cells yield no differences. In N. fossombronioides the mar- 
ginal cells average about 23 n and the median about 36X31^) these measurements 
coming well within the extremes found in the more variable N. obovata. There 
are, however, a few differences even in the vegetative organs. In iV. obovata 
the rhizoids rarely extend to the vicinity of the apex, owing to the fact that 
only the older parts of the stem are prostrate; they show furthermore no ten- 
dency to form a ventral longitudinal strand; and the cuticle of the leaves is 
usually striolate-verruculose, at least in part. In N. fossombronioides, on the 
other hand, rhizoids extend close to the apical region; they often show a tendency 
to form a ventral longitudinal strand; and the cuticle of the leaves is smooth. 
Although the inflorescence is normally paroicous in N. fossombronioides 
(as noted by Lindberg) a plant will sometimes give rise to a series of male bracts 
and then continue its growth vegetatively. In normal cases the number of 
male bracts formed is from three to six pairs, which is somewhat in excess of 
the number found in N. obovata. The bracts usually spread widely from a basal 
sac, and the apical portion is sometimes slightly reflexed. Even the bracts next 
1 Engler & Prantl, Nat. Pflanzenfam. I 3 : 79. 1893. 
