160 



PHYLUM BRYOPHYTA: 



male and female gametophytes with special 

 reproductive branches, sporophyte a minute 

 parasite from under female branch arms 



some reproductive branches 



Figure 10.3 Pore liverwort types, slightly enlarged. Antheridial 

 pits are the sites of male sex organs. 



leafy structures are nearly always flattened, are al- 

 most always in two or three rows, without a distinct 

 midvein; spore germination either not forming a moss 

 type gametophyte (protonema) or, at best, only a 

 rudimentary one; sporophyte a single, mostly stalked 

 capsule (a sporangium) without a region of constant 

 growth; sporangium (capsule) without moss struc- 

 tures such as a well-formed lid or a ring of "teeth" 

 surrounding the opening; capsule opening by valves 

 (Figures 10.3 and 10.4). 



Occurrence : about 5000 species; distribution essen- 

 tially world-wide, from completely aquatic situations 

 to moist soil. 



TlIAl.I.OSK (;AMI•:TOPII^•TE 



Structure: often sheet-like, lobed or divided, but 

 parts,also narrowly linear; either with equal-forked 



^sporophyte capsule 



gametophyte without special 

 branches 



hand lens view 

 showing diagnostic 

 pores (spots) 



branching and gross structure compact or without 

 equal forking and individual gametophytes tongue- 

 like; surface smooth or with a single midrib which 

 usually is forking and conforms to the equal-forking 

 growth pattern; vegetative reproduction includes the 

 dying and sloughing process; most species have the 

 male and female organs upon different gametophytes; 

 reproductive organs either upon the gametophyte sur- 

 face or at the end of stalks. Male sex organs variously 

 organized; in urn-shaped enclosing structures and 

 mostly concentrated in the center of the gametophyte; 

 in sac-like structures along the midrib; in fringed, 

 scale-like structures that join into fringed structures 

 along the midrib; also, in a specialized portion of the 

 gametophyte, an upright structure composed of a 

 stalk that bears a terminal disc-like body which con- 

 tains the male organs. The female sex organs are 

 variously organized and generally similar to male sex 

 organs. 



Reproduction: asexual, as in Anthocerotae, some 

 also by gemmae formation; gemmae formed inside a 

 part of the gametophyte that is modified into a cup- 

 like structure (gemma cup or cupule); inside of cup 

 generally producing stalked, lens-like gemmae which 

 are transported by water to a site for growth of a 

 new gametophyte; sexual reproduction typically as in 

 Anthocerotae. 



LEAFY GAMETOPHYTE 



Structure: composed of a simple or branched stem- 

 like structure with leaf-like parts but without vascular 

 tissue (xylem and phloem); leaves commonly in two 

 lateral rows plus one row of underleaves; lateral 



