The Manual of the Botany of the Northern United States / Including the District East of the Mississippi and North of North Carolina and Tennessee

by Asa Gray

12. Cephalozia. Branches all from beneath. Perianth on a short branch, mostly trigonal with the odd angle beneath.

24. Jungermannia. Simple or branching laterally. Perianth terminal, mostly laterally compressed.

c. Leaves mostly spinulose or dentate.

20. Plagiochila. Involucral leaves large; perianth laterally compressed.

§ 2. Plant-body pseudo-foliaceous with succubous leaf-like lobes.

28. Fossombronia. Perianth large, campanulate.

§ 3. Plant-body a thallus.

[*] Thallus with a distinct costa.

29. Pallavicinia. Thallus 3–6´´ wide, mostly simple, the margins sinuate or undulate. Perianth tubular, at length dorsal.

30. Blasia. Thallus 3–6´´ wide, lobed, dichotomous, or radiate, the margins pinnatifid-sinuate.