FILICES. (FERNS.) 595 



tracted; fruit-dots linear, often curved. Eich woods, W. New England to Michi- 

 gan, Kentucky, and southward along the mountains. Aug., Sept. 



7. A. thelypteroides, Michx. Fronds pinnate ; pinnce deeply pinnatifid, 

 linear-lanceolate (3' - 5' long), pale ; the lobes oblong, obtuse, minutely toothed, 

 crowded, each bearing 3-6 pairs of oblong fruit-dots. Kich woods ; not rare. 

 July. 



2. ATHYRIUM, Roth. Indusium of ike shorter (barely oblong] fruit-dots some- 

 oohat free at th,. ends, turgid or vaulted, but thin, often becoming curved or crescent' 

 shaped. 



8. A. Filix-fdemina, R. Brown. Frond 2-pinnate (l-3 high, 

 smooth), oblong or lanceolate in outline; pinnae lanceolate, numerous; the nar- 

 rowly oblong pinnules confluent on the rhachis by a narrow margin, sharply pin- 

 natifid-toothed ; fruit-dots 4-8 pairs on each pinnule. (Aspidium Filix-fcemina 

 & A. asplenioides, Swartz.) A narrow form is Aspidium angustum, Wittd. 

 Moist woods; common. July. (Eu.) 



11. DICKSONIA, L'Her. SITOLOBIUM, Desv. (Tab. 11.) 



Fruit-dots globular (small), marginal, each placed on the apex of a free vein 

 or fork, enclosed in a membranaceous cup-shaped special indusium open at the 

 top, and on the outer side partly covered by the thin apex of the fruit-bearing 

 toothlet of the frond, forming a sort of accessory indusium. Sporangia borne 

 on a somewhat elevated globular receptacle. (Character from our species, 

 which is perhaps to be separated.) (Named for J. Dickson, an English Cryp- 

 togamous botanist.) 



1. D. pmictilolmla, Hook. Minutely glandular and hairy (2 high) ; 

 fronds ovate-lanceolate and pointed in outline, pale green and very thin, with 

 strong stalks rising from slender extensively creeping rootstalks, pinnate, the 

 lanceolate pinnae twice pinnatifid and cut-toothed, the lobes oblong ; fruit-dots 

 minute, on a recurved toothlet, usually one at the upper margin of each lobe. 

 (D. pilosiuscula, Wittd. Nephrodium punctilobulum, Michx. Patania, Presl.) 

 Moist, rather shady places, very common : odorous. July. 



12. WOODS1A, R. Brown. WOODSIA. (Tab. 12.) 



Fruit-dots globular, borne on the back of simply-forked free veins ; the very 

 thin and often evanescent indusium attached by its base all around the recepta- 

 cle, under the sporangia, either small and open, or else early bursting at the top 

 into irregular pieces or lobes. Small and tufted pinnately-divided Ferns. 

 (Dedicated to Joseph Woods, an English botanist.) 



i 1. HYPOPELTIS, Torr. Indusium conspicuous, at first perfectly enclosing the 

 sporangia, but early opening at the top, soon splitting into several spreading jagged 

 lobes. 



1. W. obtusa, Torr. Frond broadly-lanceolate, minutely glandular- 

 hairy (6' -12' high), pinnate; the pinnae rather remote, triangular-ovate or ob- 

 long (!' or more long), bluntish, pinnately parted ; pinnules oblong, very 



