SALVINIACEAE 5 



3. A. platyneuron (L.) Oakes. Ebony Spleenwort. Besembles 

 the last, but with thinner and longer pinnae : aori 4-12 pairs, rather 

 crowded, nearer the midrib than the margin — On mossy rooks on the 

 bluffs at Courtney. Two stations, one of which has been destroyed. 

 There are but few plants at the other. July-November. 



9. ADIANTUM L. 



Fronds much divided. Sori marginal, covered by a reflexed and altered 

 portion of the pinnule, which serves as an indusium. 



1. A. pedatum L. Maiden Hair FjCBN. A very graceful fern, Q'-SO' 

 high : fronds reniform in outline, forking at the top of the dark stipe, 

 each fork with 3-7 radiating pinnae, each pinna with from 10-40 alter- 

 nate, stalked pinnules : pinnules broadly triangular, entire along lower 

 margin, upper margin more or less cleft : sori usually five to each pin- 

 nule, borne along the upper margin. — Rather common in rich woods. 

 July-November. 



10. PELLAEA Link. 



Sori marginal, at length forming a continuous marginal line, and 

 covered by the reflexed portion of the frond, which serves as the 

 indusium. 



1. P. atropurpurea (L.) Link. Cliff Brake. ^'-W high: root- 

 stock densely chaffy : stipe and rachis purplish-black, usually strongly 

 puberulent : fronds coriaceous, twice pinnate, ovate-lanceolate in outline : 

 pinnules 3^-12''' long, oblong-linear, crenulate. — Rather common on 

 limestone rocks. June-September. 



Var. Bushil Mackenzie, n. var. Stipe and rachis brownish-red, but 

 slightly hairy : fronds thinnish, simply pinnate above, the lower pinnae 

 ternate or rarely quinate. — Dry rocks at Swope Park. 



11. NOTHOLAENA E. Br. 



Fronds pinnate. Sori roundish, marginal, at first covered with the 

 inflexed margin of the pinnules, but with no proper indusium. 



1. N. nivea dealbata (Pursh) Davenp. Powdery Cliff Brake. 

 A small, densely tufted fern, V-V high ; stipe, rachis and branches 

 brown and shining : fronds triangular-ovate in outline, 3-4-pinnate : 

 ultimate segments 1" long, usually entire. — In clefts of limestone rooks 

 throughout the western and southern parts. Not uncommon. June- 

 September. 



Family 4. SALVINIACEAE Eeichenb. 



Small floating plants with elongated, often branching axis and two- 

 ranked leaves, having two or more thin-walled, 1-celled sporocarps on a 

 common stalk. Sporocarps with a central receptacle bearing macrospo- 

 ranges containing one macrospore, or microsporanges containing numerous 

 microspores. 



