8o UNIVERSITY OF MISSOURI STUDIES [32 3 



5. POLYSTIOHUM Rich. [DRYOPTERIS Ad- 

 ans. : ASPIDIUM Swartz]. 



6. P. acrostichoides (Michx.) Kuntze \p. acrostichoides 



(Michx.) Kuntze: A. acrostichoides (Michx.) Swartz]. 

 Christmas fern. 

 In oak forests and thickets; common. Some remarkable 

 fronds, gathered in the forest south of Grindstone creek, 

 July, 1903, have all the pinnae fertile. 

 Nova Scotia to Kansas and Florida. 



6. SOOLOPENDRIUM Smith [^CAMPTOSORUS 

 Link]. Hartstongue. 



7. S. rhizophyllum (L.) Hook. [C. rhizophyllus {\^) Link]. 

 Walking fern. 



Moist limestone rocks and cliffs; densely gregarious. 

 Quebec and Michigan to Kansas and Georgia. 



7. ASPLENIUM L. Spleenwort. 



8. A. platyneuron (L.) Oakes \A. ebeneum (L.) Ait.]. 

 Ebony fern. 



Common in wild places in rocky ground. 

 Maine to Colorado; Florida to Texas. 



9. A. pycnocarpon Spreng. \^A. a?tgustifolium Michx., not 

 Jacq.] Narrow-leaved spleenwort. 



Rich ravines in shady or half-open places. 



Quebec to Wisconsin; Georgia to Alabama; Missouri. 



8. PELLAEA Link [NOTHOLAENA R. Br.]. 

 Cliff-brake. 



ID. P. atropurpurea (L.) Link. Common cliff-brake. 

 Dry cliffs and rocks; common. 

 Ontario to British Columbia; Georgia to Arizona. 



II. P. dealbata (Pursh) Daniels \_N. dealbata (Pursh) 

 Kuntze: N.7iivea dealbata {Vwrsh) Dav.]. Snowy cliff- 

 brake. 

 Cliffs of the Missouri near Rocheport; exceedingly rare. 

 Missouri and Nebraska to Texas and Arizona. 



