8 POLYPODIACEAE. 



Family 5. POLYPODIACEAE R. Br. Prodr. Fl. Nov. Holl. i : 145. 1810^ 



FERN FAMILY. 



Ferns of various habit, the rootstocks horizontal, often elongated, or short 

 and erect, the leaves simple, pinnate, pinnatifid or decompound, coiled in ver- 

 :i. Sporanges home in clusters (sori ) on the lower side or margins of the 

 s or their segments, stalked, provided with a vertical ring of cells, open- 

 ing transversely. Sori with or without a membranaceous covering (indusium). 

 Prothallium green. 



About 70 genera and 3000 species of very wide geographic distribution. The famil y includes 

 by far the gn.-aU.-r number of living ferns. 



Spore-bearing leaves closely rolled together, with necklace-like segments. 



i. Onoclea. 

 leaves all flat or their edges only slightly revolute. 



rf dorsal nr marginal, provided with special indusia. 

 Sori roundish, indusia less than twice as long as broad. 

 Indusium wholly inferior. 



Indusium roundish or stellate. 2. Woodsia, 



Indusium cup-shaped or somewhat 2-valved. 3. Dicksonia. 



Indusium partly inferior, fixed by a broad base and enclosing the sori like a hood. 



\. Cystopteris. 



Indusium superior, fixed by its centre or sinus. 5. Dryopteris. 



Sori linear or oblong ; indusia more than twice as long as broad. 



Sori in chain-like rows parallel to the midribs or rachises. 7. Wooduuardia. 



Sori all oblique to the midrib or rachises : veins free. 



Sori confluent in pairs with an apparently double indusium opening in the middle ; 



leaf simple. 8. Scolopendrium. 



Sori single on the upper side of a veinlet or rarely crossing it. 



10. Aspleniiim. 

 Sori partly parallel to the midrib, partly oblique: veins united. 9. Camptosorus. 



Sori with marginal indusia formed of the more or less altered edge of the leaf. 

 Sporanges at the ends of veins, borne on a reflexed portion of the leaf. 



11. Adiau/tiin. 

 Sporanges borne on a continuous vein-like receptacle which connects the apices of the 



vci- 12. Pteris. 



Sporanges at or near the ends of unconnected veins. 



- of two forms ; stipes pale. 13. Crypiogramma. 



Leaves uniform ; stipes usually dark colored. 



Sori mostly forming a continuous indusium around the segment. 



14. Pellaea. 

 Sori minute ; indusium usually interrupted, if continuous the segments small and 



bead-like. 15. Cheilantlics. 



A ithout indusia. 



Sori linear and marginal. 16. Notholaena. 



Sori roundish or not more than twice as long as broad. 



Stipes articulated to the rootstocks ; leaves in our species pinnatifid. 



17. Poly pod turn. 



Stipes not articulated to the rootstocks ; leaves in our species 2-3-pinhatifid or ternate. 



6. Phegoptcris. 



i. ONOCLEA L. Sp. PI. 1062. 1753. 



Coarse ferns with the fertile leaves closely rolled up into necklace-like or berry-like 

 segments, and entirely unlike the broad pinnatifid sterile ones. Sori round, borne on the 

 b*ck of the veins. Indusium very thin and membranous, hemispheric or hood-shaped, fixed 

 t the inferior side of the sorus. Sporanges pedicelled, provided with a dorsal ring, burst- 

 ing transversely. Fertile leaves unrolling at maturity, allowing the spores to escape, and 

 remaining long after the sterile leaves have been killed by frost. [Name ancient, not 

 originally applied to these plants.] 



in Nort^Vnurica nat ' Ve * f cold and *? regions. Only the following are known to occur 



Fertile leaf bipinnate ; veins anastomosing. , Q 



V..f s, mi ,u. 1)lnn , u . . v , ms fr ,, J- O. 



