CLUB MOSSES 93 



species, but they all resemble each other by having simple 

 or dichotomously branched stems from which grow numerous 

 small often scale-like leaves completely covering the stem 

 in some species. The tissues of the stem are differentiated 

 and there is a single large central fibrovascular bundle con- 



FIG. 52. Lycopodium lucidulum showing 1, bifurcated stem covered with 

 leaves; 2, roots; 3, rhizome. 



sisting of several groups of xylem alternating with phloem 

 and surrounded' with an endodermis. 



The long tough roots grow from the base or sides of the 

 stems. 



The leaves of the simplest lycopodiums all bear sporangia 

 in their axils; they are therefore sporophylls. In other species 



