GUIDE 



GROUP III 



FERTILE FRONDS UNIFORMLY SOMEWHAT LEAF-LIKE IN 



APPEARANCE, YET DIFFERING NOTICEABLY FROM 



STERILE FRONDS 



15. SLENDER CLIFF BRAKE 



Pellaa gracilis 



A small fern, 1-3 pinnate. Very delicate. Fertile fronds taller, 

 more contracted and simpler than the sterile, sporangia bor- 

 dering the pinnae. Usually on sheltered rocks, preferring lime- 

 stone. P. 87. 



16. PURPLE CLIFF BRAKE 



Pellaea atropurpurea 



Medium sized, 1-2 pinnate, leathery. Fertile fronds taller and 

 more contracted than the sterile, sporangia bordering the pinnae. 

 Usually on exposed rocks, preferring limestone. P. 90. 



17. CHRISTMAS FERN 



Aspidium acrostichoides 



Rather large, smooth and glossy, once-pinnate. Fertile fronds 

 contracted at the summit where the fruit appears. In rocky woods. 

 P. 96. 



18. NARROW-LEAVED SPLEENWORT 



Asplenium angustifoliwn 



Tall and delicate, once-pinnate. ..Fertile fronds taller and narrower 

 than the sterile. In moist woods in late summer. P. 98. 



19. NET-VEINED CHAIN FERN 



Woodwardia angnstifolia 



Large, fronds deeply pinnatifid, the fertile taller and more con- 

 tracted than the sterile. In wet woods near the coast. P. 102. 



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