SALVINIACEAE 5 



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

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

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

 bluffs at Courtnej'. 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. Maidex Hair Fern. A very graceful fern, 9'-20^ 

 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. 2^-12^ 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 R. 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-i^ high : stipe, rachis and branches 

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

 ultimate segments V^ long, usually entire.- — ^In clefts of limestone rocks 

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

 September. 



Family 4. SALVINIACEAE Reichenb. 



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. 



