1	"Cells in divergent rows at the ±auriculate leaf base"	2
1	"Cells in vertical rows; leaf base not auriculate"	3
2	"Leaves generally 3-plicate; laminal cells unipapillose"	Meteorium
2	"Leaves, if plicate, with only 1 or 2 plicae; laminal cells multipapillose"	Papillaria
3	"Plants slender; leaves narrow, lanceolate; apex filiform or flexuose-capillaceous, rarely acuminate"	4
3	"Plants robust; leaves broader, ovate; apex always acuminate"	5
4	"Leaves widely spreading, multipapillose; cell outline ±obscure; costa reaching mid-leaf"	Floribundaria
4	"Leaves ±appressed, scarcely papillose, ±ecostate; cell outline distinct"	Barbella
5	"Leaves appressed; apex transversely undulate; costa extending more than two-thirds of the leaf length"	Aerobryopsis
5	"Leaves spreading to squarrose; apex straight; costa extending to half of the leaf length"	Meteoriopsis