EMBRYOPHYTA PTERIDOPHYTA 



313 



FILICALES 



Leafy plants, fronds usually raised on a stipe; coming from a rootstock; 

 leaves usually rolled up in the bud, circulate; spores all of one kind and size, 

 produced in sporangia which occur on the back of the frond, these at maturity 

 break open and discharge the minute spores, which develop prothalli that bear 

 the antheridia and archegonia. The following sub-orders occur in the United 

 States : the Ophioglossaceae represented by the common adder's tongue, 

 Ophioglossum vulgatum, found in moist meadows, the Moonwort, Botrychium 

 Lunaria and B. Virginianum; the Osmundaceae, large ferns with straight erect 

 rootstocks, pinnate leaves; large globose sporangia with mere traces of a ring; 

 the Royal fern, Osmunda regalis, Clayton's fern (O. Claytonia), the most 

 common species in damp woods, and the Cinnamon Fern (O. cinnamomecty, 

 occurring in wet places, marshes, etc. ; the Filmy ferns, Hymenophyllaceae, 

 represented by the Bristle Fern (Trichomanes radicans} ; Cyatheaceae with such 

 tree ferns as Dicksonia ; Polypodiaceae, Common Brake, Maidenhair fern ; 



Fig. 117. Marsilia (M. 

 quadrifolia), a young leaf. 

 *. Fruiting body. Bischoff. 



Fig. 117a. Club moss (Lycopodium clavatum). 1. Plant 

 with fertile shoots. 2. Scale and the sporangium. 3. Spores. 

 After VVossidlo. 



