12 COMPENDIUM. 



uniting the bases of the veins, often more or 

 less produced- along the veins in the direction 

 of the margin. 

 Tribe X. Polypodieae. 



GENUS 71. POLYPODIUM. Sori round or oblong, 

 several to numerous on each side of the costa. 

 Fronds uniform or dimorphous, simple or divided ; 

 barren fronds never oak-leaf-like ; surfaces naked, 

 scaly or hair,y, the hairs not stellate; veins 

 free or anastomosing regularly, with the areolae 

 provided with included free veinlets running in 

 the direction of the margin. Rhizome scales 

 present. 



GENUS 71a. PLEOPELTIS. Like genus 71, but 

 the sori sometimes linear, the veins anastomosing 

 irregularly, and the areolae with the free 

 veinlets mostly spreading in various directions. 



GENUS lib. LECANOPTERIS. Like genus 71, but 

 the sori placed on marginal outgrowths of the 

 deeply pinnatifld or pinnate fronds, and the 

 venation as in genus 7 Iff. Rhizome scales 

 wanting. 



GENUS 73. DRYNARIA. Sori round, copious, on 

 non-contracted segments. Fronds dimorphous ; 

 barren fronds (cup-leaves) oak-leaf-like, sessile, 

 humus-collecting; fertile fronds pinnatifld or 

 pinnate, stalked, not humus-collecting; veins 

 anastomosing copiously. 



GENUS 73a. THAYERIA. Like genus 73, but the 

 sori restricted to the much contracted higher 

 segments of the fertile fronds. Fronds dimorphous, 

 if not, then both barren and fertile fronds humus- 

 collecting. 



GENUS 74. DRYOSTACHYUM. Like genus 71a, 

 but the sori round or oblong, restricted to the 

 much contracted higher segments of pinnatifld 

 or pinnate fronds, springing from the veins 



- . and the parenchyma. 



