KEY TO THE PHYLA 329 



2. Cellular filamentous hysterophytic plants, 

 often much degenerated, without chloro- 

 phyll; heterogamic. 



Phylum 7. CARPOMYCETEAE. 



II. Plants of two obvious, alternating generations, typ- 

 ically terrestrial. 



a. Gametophyte generation larger, and longer-lived 



than the dependent sporophyte generation. 

 1. Gametophytes from prostrate and thalloid to 

 erect leafy shoots; sporophytes globose to 

 cylindrical or stalked, neither expanded nor 

 rooted. 



Phylum 8. BRTOPHYTA. 



b. Gametophyte generation smaller and shorter- 



lived than the independent sporophyte 

 generation. 



1. Both generations mostly holophytic, independ- 



ent of one another. 



(a) Gametophytes typically flat and thal- 

 loid, normally attached by rhizoids, 

 mostly monoecious; sporophytes consist- 

 ing of large-leaved, solid stems, which 

 are rooted below. 



Phylum 9. PTERIDOPHYTA. 



(b) Gametophytes typically flat and thal- 

 loid, normally attached by rhizoids, 

 mostly monoecious; sporophytes con- 

 sisting of mostly solid, cylindrical, 

 jointed and fluted stems, bearing small, 

 whorled leaves at the nodes, and rooted 

 below. Phylum 10. CALAMOPHYTA. 



(c) Gametophytes typically tubular or glo- 

 bose, with few rhizoids or none, often 

 dioecious; sporophytes consisting of 

 solid, cylindrical, continuous (not joint- 

 ed) and not fluted stems, bearing small 

 spirally arranged (or opposite) leaves, 

 and rooted below. 



Phylum 11. LEPIDOPHYTA. 



2. Gametophytes hysterophytic, dependent upon 



and nourished by the sporophyte. 



