ORDER 109. FILICES. 



x Indusium cupform. fringed, fixed beneath all around the sorus WoODSlA. 31 



a. Indusinm hoodfurm, fixed by the base and 2 sides CISTOPTERIS. 32 



x Indusium reniform, opening only toward the margin of the segm. Fla...NEPHROLKPis exaltnta. 

 x Indusiura round-renifonn, fixed in the midst, open all around ASPIDIUM. 33 



1. OFHIOGLOSSUM, L. ADDER'S TONGUE. Sporangia roundish, na- 

 ked, opening transversely, arranged in two rows along the margins of the 

 iVrlile, contracted, spike-like frond. Veins reticulated. 



1 O. v u] a tu ni L. Root of thick fibres; stem simple, bearing 1 oblong-ovate, en- 



ure, smooth frond, 23', with no mid-vein, and a terminal spike, 12'. A cut ions 

 little plant, in low grounds. Vernation straight, as in all this section, not circinate. 



2 O. bulbosum L. Root a globular conn ; frond ovate to reniform. on the stem close 



to the ground. Wet pine-barrens, N. J., and S. Often 2 stems from 1 conn. 



2. BOTRYCHIUM, Swartz. MOONWORT. GRAPE FERN. Sporangia 

 subglobous, 1-celled, 2-valved, distinct, coriaceous, smooth, adnate to the 

 compound rachis of a racemous panicle. Valves opening transversely. 



Frond ternately divided, segments palmately veined Nos. 1, 2 



Frond pinnately divided, segments piunately veineU Nos. 3 5 



1 B. lunarioides Swtz. Scape 8 12', bearing a stalked frond near the base and a 



panicle of numerous little 2-ranked spikes at the top ; frond in 3 bipinnatifid divi- 

 sions : segment obliquely lanceolate, crenulate. Shady pastures and woods. 

 p. dtsstctunit Frond more numerously dissected, almost tripinnatifid. 



2 B. simplex Hitchcock. Frond simple, or 3-lobed or parted, segm. broad-wedge- 



obovate, small, incised or subentire, unequal ; spike compound, interrupted, smal!. 

 Dry hills, Vt, Mass. Whole plant 36'. Frond 612", short-stalked, near the base. 



3 B. neglectum Wood. Frond 1 2 r , simply pinnate, with oval or ovate incised pin- 



nse, short-stalked, on upper part of stem, which is 58' high. Pan. 12'. N. H., Vt., to 

 Pa. Prof. Porter regards both this and No. 2 as var. of B. matricarisefolium Braun. 



4 B. lanceolatiim Angst. Frond bipinnatifid, closely sessile, triangular in outline 



with lanceolate, incised segments ; panicle 2- or 3-pinnate. N. J., Pa., to L. Sup. (O. B. 

 Wheeler). Certainly distinct from No. 3. 



5 B. Virginicum L. Rattlesnake Fern. Stem 1 2f, with the large (5 S') tripin.,tri 



angular frond sess. at or above the middle; ultimate segm. obtuse, 3-5-toothed; pan. 

 decompound, 36'. reddish br. A beautiful Fern, in damp woods, not uncom. Jn., Jl. 



3. OSMUNDA, L. FLOWERING FERN. Sporangia globular, half 2- 

 valved, roughened on the surface somewhat in lines, pedicellate and clus- 

 tered on the lower surface of the frond or a portion of it, which is more or 

 less contracted into the form of a panicle. Spores green. Tall, hand- 

 some Ferns. Veins forked, straight. June. 



Frond bipinnate with distinct pinnae, the upper part contracted and fertile.... No. 1 



Frond pinnate with pinnatifid pinnae, partially or separately fertile NCJ. 2, 3 



1 O. regalis MX. A large and beautiful Fern in meadows and swamps ; fronds 34 f, 



glabrous, bipinnate, fruiting above in an ample panicle ; pinnae with 69 pairs of 



distinct, oblong, serrulate, subsessile leaflets ; fruit rust-colored. 

 2t O. einnamome L. Sterile fronds pinnate, in clumps 3 5f ; pinnae pinnatifid with 



ovate-oblong, obtuse, entire segments ; fertile frond bipinuate, pinnae all contracted, 



panicled, clothed with c'vnamou-colored wool. 

 3 O. Clay toiiia.ua L. Fronds ample, 2 3f, smooth, pinnate, the pinme lance-linear, 



pinnatifid, some of the intermediate ones fertile, contracted and raceme-like. 



4. LYGODIUM, Swartz. CLIMBING FERN. Sporangia sessile, arranged 

 in 2-rankcd spikelets issuing from the margin of the contracted frond, open- 



