536 The Ohio Naturalist. [Vol. VI, No. 7, 



Liochlaena Nees. 



Monoecious. Dark Green. Stem with brownish rootlets, closely 

 creeping, usually branched many times; leaves imbricate, 

 mostly decurrent; leaf cells large, roundish, with much thick- 

 ened walls; involucral leaves vertical and saccate in their 

 lower part, recurved and spread out flatly in their upper part. 



lanccolata Nees. 

 Lophocolea Dumrrt. 



1. Leaves entire, emarginate and bidentate (often on the same stem), 



leaves 2-lobed, lobes- mere or less dentate. heieropylla Nees. 

 Underleaves (all) dis'tincfly bilobed. 2. 



2. Underleaves ^i to 4 cleft -or 2 and 3 to 4 parted. 3. 

 Underleaves 2-lobed. . 4. ■ • ^ 



3. Underleaves 3 to 4 cleft, the inner lobes lanceolate, the outer ones 



linear; leaves acutely lobed. bidentata Dumort. 



Underleaves, the lower small, 2-parted, the upper larger with a 

 signle tooth on each side or palmately 3-4 parted and the 

 apical sublanceolate and narrowly bifid; leaves mostly ob- 

 tusely lobed. Hallii Aust. 



4. Leaves 2-lobed with obtuse sinus and lobes or refuse or entire; 



underleaves light-pink, the steaceous lobes spreading incruved. 



Macoiinii Aust. 

 Leaves 2-lobed Avith acute lobes and acute or obtuse sinus. 5. 



5. Leaf lobes with an obtuse (lunate) sinus, usually bearing yellowish 



globules, lobes of underleaves lanceolate, acuminate. Dioe- 

 cious, minor Nees. 

 Leaf lobes usualh' with an acute sinus; lobes of underleaves subu- 

 late. Monoecious. Aiistini Lindb. 



Litnularia Micheli. 



Thallus oblong with rounded lobes, aereolate and porcse, innova- 

 ting from the apex, with imbricate sublunate scales beneath; 

 peduncle very hairy; antheridia in the apical sinus of the 

 thallus. vulgaris Raddi. 



Marchantia Marchant f. 



Thallus large, forking, areolate, porcse; receptacle divided into 

 an uneven number of rays (mostly 9) and the involucres be- 

 tween them always one less in number. Antheridia immersed 

 in a peduncled, disk-like, raidate, or lobed receptacle. Dioe- 

 cious, polymorplia L. 



Marsupella Dumort. 



1. Leaves closely and vertically iml:)ricate; stem minute (2-4 mm.), 



clavate with 4-S pairs of oval leaves; leaves \-\ bilobed, lobes 

 acute with an acute or angular sinus. adiista Spruce. 



Leaves spreading or locsely imbricate. 2. 



2. Stem stoloniferous, rigid (10-40, sometimes 80-100 mm.), some- 



what thickened upward; leaves usually broader than long, 

 subquadrate, lobes obtuse or mucronate; sinus obtuse (^ or 

 ^ of the leaf) ; the two upper involucral leaves connate to 

 the middle. cmarginata Dumort. 



Stem not stoloniferous, erect, subflexuous (15-30 mm.); leaves 

 obovate, their upper half slightly keeled, their lower half 

 ventricose-concave; lobes roundish-obtuse, sinus narrow, 

 acute or less obtuse than in the perceding (i of the leaf); 

 the two upper involucral leaves connate J. 



sphacelata Dumort. 

 Mctzgcria Raddi. 



1. Densely villous throughout. piibesccns Raddi. 



Hairy on the margin and midrib beneatlT, smooth above. 2. 



