FILICE8. (ferns.) 595 



traded; JruU-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. — Eich woods ; not rare. 

 July. 



§ 2. ATH I EIUM, Eoth. — Indusium of the shorter (hardy oblong) fruit-dots some- 

 Bohat free at the ends, turgid or vaulted, but thin, often becoming curved or crescent- 

 shaped. 



8. A. Filix-foemina, E. Brown. Frond 2-pinnate (l°-3° high, 

 smooth), oblong or lanceolate in outline ; pinnss lanceolate, numerous ; the nai^ 

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

 natifid-toothed ; fruit-dots 4-8 pairs on each pinnule. (Aspidium Klix-foemina 

 & A. aspleuioides, Swartz.) — A narrow form is Aspidium angustum, Willd. — 

 Moist woods; common. July. (Eu.) 



11. DICKSOIVIA, L'Her. § SITOLOBIUM, Desv. (Tab. 11.) 



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

 or fork, enclosed in a membranaceous cap-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 .7. Dickson, an English Cryp- 

 togamous botanist.) 



1. D. puiictil61>nla, Hook. Minutely glandular and hairy (2° high) ; 

 fi-onds 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, Willd, Nephrodium punctilobulum, Michx. Patania, Pred.) 

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



12. "WOODSIA, E. 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.) 



S 1_ HYPOPifcLTIS, Torr. — Indusium conspicuous, at first perfectly enclosing the 

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

 lobes. 



I \f, obttlsa, Torr. Frond broadly-lanceolate, minutely glandular- 

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

 long (1' or more long), blimtish, pinnately parted ; pinnules oblong, very 



