122 LEJEUNEAE OF THE UNITED STATES AND CANADA 
14. Lobes and underl distinctly crenulate on the margins, underleaves smaller than 
13. Lejeunea patens. 
15. 
lobules. 
Lobes and underleaves entire.or nearly so. 
15. Plants pale to dark green, underleaves as large as lobules or larger, not rounded at 
base, perianth abruptly narrowed at base. 14. Lejeune ia. 
Plants pale, underleaves larger than lobules, rounded at base, perianth gradually 
narrowed toward base. 15. Lejeunea Americana, 
16. Median leaf-cells 18-20 u in diameter. I7: 
Median leaf-cells 12-13 u in diameter. 18. 
17. Underleaves longer than broad, deeply bifid, often unidentate on sides. 
Microlejeunea lucens. 
Underleaves as broad as long, bifid to middle, never unidentate on sides. 
17. Microlejeunea Ruthit. 
18, Lobule much smaller than lobe, often obsolete, lobe indistinctly ocellate at base, 
averaging 0.25 mm. in length. 18. Microlejeunea Cardoti. 
Lobule nearly as large as lobe, lobe not ocellate at base, averaging 0.17 mm. in 
length. I9. Microlejeunea bullata. 
. Lobule three fourths the length of lobe or longer, lobe rounded at the apex and 
without hyaline cells, crenulate on the margin, stylus reduced to a single papilla, 
- 
o 
inflorescence autoicous 20. Cololejeunea minutissima. i 
Lobule about half as long as lobe. : 
Outer surface of lobe rough from projecting cells or wart-like thickenings or both, 
hyaline cells absent, inflorescence dioicous or autoicous, 21. 
Outer surface of lobe almost smooth, the cells scarcely if at all convex, hyaline 
cells often present at the apex and along antical margin, stylus usually two cells 
long, inflorescence synoicous or paroicous, 23. Cololejeunea Jovriana. 
Y 
9 
to 
- 
: Lobe narrowed toward the apex, with strongly convex or conical cells, the project- 
ing wall sometimes thickened, stylus usually two to ten cells long. 
Cololejeunea Biddlecomiae. 
a. 
Lobe broad at the apex, with slightly convex cells, each bearing in the middle a 
large globoid thickening, stylus usually two cells long. 
22. Cololejeunea ۵ 
DESCRIPTION OF SPECIES 
1. ARCHILEJEUNEA CLYPEATA (Schwein.) Schiffn. 
PLATE 16, Fics. 1-11 
Jungermannia clypeata Schwein. Spec. Fl. Amer. Sept. Crypt. 
Hep. 12: 1831: 
Jungermannia transversalis Schwein. L c. (not Swartz). 
Phragmicoma clypeata Nees, Naturgesch. Eur. Leberm. 3: 
248. 1838. 
Lejeunea Dorotheae Lehm. Pugillus, 7:15. 1838. GER 
N. Syn. Hep. 332. 1845. 
