336 ' Alexander W. Evans, 



and triangular with bulging sides, one side being usuall}' shorter 

 than the other two; sometimes one or two of the sides are concave 

 or wavy, making the trigones irregular (Fig. 10, C). In the middle 

 of the lobe intermediate thickenings are infrequent; toward the 

 margin, however, as well as on the lobules and underleaves, they 

 are much more abundant. They are mostly oval with bulging 

 sides but are sometimes more irregular. Except in the middle 

 portion of the lobe coalescence between thickenings often occurs. 



The inflorescence is autoicous. The archegonia are borne on 

 an elongated branch, which is more or less subdivided, one of the 

 branches arising among or just behind the bracts. According to 

 Spruce the latter are in seven pairs, according to Stephani in three. 

 The writer has found the number of pairs to vary from two to five. 

 The bracts increase rapidly in size toward the perianth, those of the 

 innermost pair having lobes about 3.5 mm. long and 1..5 mm. wide. 

 The innermost bracts are free from each other at the antical base 

 but are highly connate with the bracteole and form with it a widely 

 spreading o})en cup, in the bottom of which the perianth is situated. 

 The lobes of these bracts are plane, ovate in outline, and acuminate 

 at the apex. In most cases they are sharply and coarsely dentate 

 or spinose above the middle, but in some cases they are nearly 

 or quite entire. When teeth or spines are present the maximum 

 number is perhaps seven on the outer margin and five on the inner. 

 The lobule is about as long as the lobe but narrower, and it appears 

 narrower than it really is on account of its re volute margins. The 

 apex forms a long and slender point, and there is usually if not 

 always a slender tooth, representing the stylus, close to the junction 

 with the bracteole. Aside from the stylus the margin of the lobule 

 may be either entire or else irregularly toothed or spinose. The 

 bracteole is about 2.7 mm. long and 1 mm. wide; it is deeply bifid, 

 the broad and rounded sinus extending nearly or quite as far back 

 as the clefts between the bracteoles and the lobules of the bracts. 

 The divisions of the bracteole are much like the lobules, being long- 

 pointed and with revolute margins, while the latter are either entire 

 or variously toothed. The remaining bracts and bracteoles show 

 a gradual transition toward normal leaves and underleaves. 



The perianth, which is terete or slightly compressed, is narrowly 

 oblong or ovate in outline ; it measures 3—4 mm. in length and about 

 0.9 mm. in width and extends slightly or not at all beyond the 

 involucre. At the apex it is rounded or truncate and bears a long 

 slender beak, the throat of which is closed by short internal papillae, 

 rarely reaching the minutely crenulate mouth. Except in the basal 



