A. W. Evans — JVorth American S2oecies of Frullania. 15 



and bearing numerous scattered tubercles or scales, especially on the 

 keels : 3 plant not seen. 



Stem O'lS™"" in diameter ; lobes of leaves 0-80™™ long and wide, 

 lobule 0-23'""' long, 0-20™™ Avide ; underleaves 0'45"'™ long, 0-35™'" 

 wide; leaf-cells from edge of lobe O'OIG™™ in diameter, from middle 

 0-027™'" long, 0-01 Q""" wide, and from base O-OSO"""^ long, 0-023™'^ 

 wide ; bract I, lobe l-OO'""^ long, 0-80™'" wide, lobule O-VS"""" long, 

 0.40mm ^yi^^ig . bracteole I, 0-75""'" long, 0-60'""" wide ; bract II, lobe 

 O-gomm \qx\^, 0-75'"" wldc, lobulc 0-65""" long, 0-30'"'" wide ; bracteole 

 II, 0-55'"™ long, 0-30"'"^ wide; perianth l-50'^"^ long, 0-90"'"' Avide. 



On trees and rocks, from Connecticut to Ohio and southward ; 

 common in the Southern States. Distribi:ited in Hep. Bor.-Araer. 

 n. 100 and in Hep. Amer. n. 9Jf.. 



Frullania sqiiarrosa is the most cosmopolitan of all our species, 

 occurring almost everywhere in the warmer parts of the earth. The 

 species is commonly sterile and plants with perianths are extremely 

 rare, although female plants without perianths are not unusual. 

 Even in a sterile state there is no difficulty in distinguishing the 

 plant, because the densely imbricated leaves, closely appressed to the 

 stem when dry and strongly squarrose when moist, are unlike any- 

 thing found in our other species. In the Southern States a form 

 with the lobules prett^^ uniformly explanate sometimes occurs : this 

 is apparently J^'M^to^AKi ei'icoides Nees, but there seems to be no good 

 reason for keeping it distinct from F. sqiiarrosa even as a variety. 



8. Frullania Brittonise n. sp. 



Frullania dilatata Underw. in Gray: Manual of Botany, sixth edition, 706. 1890 

 (not (L.) Dum.). 



Plate VII. figs. 1-12. 



Dioicous : plants growing in wide depressed tufts, reddish-brown 

 varying to greenish: stems irregularly pinnate: leaves imbricated, the 

 lobe reniform-orbicular arching over the stem and strongly cordate 

 or auriculate at base, plane or decurved at the rounded apex, entire ; 

 lobule galeate, close to the stem, truncate and compressed at base, 

 inflated in upper and outer parts ; stylus subulate, three to five cells 

 wide at base : underleaves distant, broadly orbicular or elliptical, 

 bifid about one third with obtuse, acute or apiculate lobes and acute 

 sinus, irregularly dentate or crenulate on the sides above the middle: 

 leaf -cells at margin of lobe with rather thin walls, distinct ti-igones 

 and occasional intermediate thickenings, the last becoming fewer, 

 the walls thicker and the trigones more conspicuous as we pass 

 inward : ? inflorescence terminal on the stem or a principal branch ; 

 bracts in two or three pairs, unequally bifid, the lobe ovate, rounded 



