THE GREAT GROUPS OF PTERIDOPHYTES 



163 



FIG. 137. A common club-moss (Lycopodium davatutn): 1, the whole plant, showing 

 horizontal stem giving rise to roots and to erect branches bearing strobili; 2, a 

 single sporophyll with its sporangium; 3, spores, much magnified. After Wos- 



8IDLO. 



88. Lycopodium. This genus contains fewer forms than 

 the other, but they are larger and coarser and more charac- 

 teristic of the temperate regions, being the ordinary Club- 

 mosses (Fig. 137). They also more commonly display 

 conspicuous and distinct strobili, although there is every 



