FILICES. (FERNS.) 599 



a A. acille:\tlim, Swartz, var. B rail 111 i, Koch. Frond spreading, 

 % -pinnate (l-2 long), oblong-lanceolate in outline, with a tapering base, the 

 lower of the many pairs of oblong-lanceolate pinnae gradually reduced in size 

 and obtuse ; pinnules ovate or oblong, obtuse, truncate and almost rectangular 

 at the base, short-stalked, or the upper confluent, sharply toothed, beset with 

 long and soft as well as chaffy hairs. (A. Braunii, Spenner.) Deep woods, 

 mountains of New Hampshire, Vermont, N. New York, and northward. (Eu.) 

 * # Fronds simply pinnate, mostly upright, 



9. A. acrosticlioides, Swartz. Frond lanceolate (l-2 high), 

 stalked ; pinnce linear-lanceolate, somewhat scythe-shaped, half-halberd-shaped at 

 the slightly stalked base, serrulate with appressed bristly teeth ; the fertile (upper) 

 ones contracted and smaller, bearing contiguous fruit-dots near the midrib, which 

 are confluent with age, and cover the surface. (Nephrodium acrostichoides, 

 Michx.) Var. iNclsuM (A. Schweinitzii, Beck) is a state with cut-lobed 

 pinna?, a not unfrequent case in the sterile fronds ; sometimes the tips of almost 

 all of them fertile more or less. Hill-sides and ravines in woods ; common 

 northward, and southward along the Alleghanies. July. 



10. A. LonchltiS, Swartz ? Frond linear-lanceolate (9' - 20' high), scarce- 

 ly stalked, very rigid ; pinnce broadly lanceolate-scythe-shaped, or the lowest triangular, 

 strongly am-icled on the upper side and wedge-truncate on the lower, densely 

 spiny-toothed (!' or less in length), copiously fruit-bearing; fruit-dots contigu- 

 ous and near the margins. Woods, southern shore of Lake Superior, and 

 northwestward. (Eu.) 



15. ONOCL.43A, L. SENSITIVE FERN. (Tab. 12.) 



Fertile frond twice pinnate, much contracted ; the pinnules short and revolute, 

 usually so rolled up as to be converted into berry-shaped closed involucres filled 

 with sporangia, and forming a one-sided spike or raceme. Fruit-dots one on 

 the middle of each strong and simple primary vein (with or without sterile cross- 

 veins), round, soon all confluent. Indusium very thin, hood-like, lateral, fixed 

 by its lower side, free on the upper (towards the apex of the pinnule). Sterile 

 fronds rising separately from the naked extensively creeping rootstock, long- 

 stalked, broadly triangular in outline, deeply pinnatifid into lance-oblong pinna, 

 which are entire or wavy-toothed, or the lowest pair sinuate-pinnatifid (decaying 

 in autumn) ; veins reticulated with fine meshes. (Name apparently from oi/oy, 

 o vessel, and KXei'eo, to close, from the singularly rolled up fructification.) 



1. O. sensibilis, L. Moist or wet places, along streams ; common. 

 July. A rare abnormal state, in which the pinnae of some of the sterile fronds, 

 becoming again pinnatifid and more or less contracted, bear some fruit-dots 

 without being much revolute or losing their foliaccous character, is the var. 

 OBTUSILOB\TA, Torr. N. Y. State Fl. (Yates County, New York, SartweU, 

 and Washington County, Dr. Smith. New Haven, Connecticut, D. C. Eaton.) 

 This explains the long-lost 0. obtusilobiUa, Schkuhr (from Pennsylvania), which, 

 as fig-ured, has the sterile fronds thus 2-pinnately divided. (Ragiopteris, Presl. 

 is founded on a young fertile frond of this species and the sterile frond of some 

 different For a.) 



