632 FIUCES. (FERNS.) 



veins simple, free, or the basal ones meeting at the sinus between the seg 

 ments ; iiulusiuin small, pubescent. Low shady woods, Florida to South 

 Carolina, and westward. Fronds l-3 high. 



4. A. conterminum, Willd., var. strigosum, Eaton. Hootstock 

 thick, erect; stipe short and scaly; frond li-3 high, oblong-lanceolate, 

 attenuate at each end, pinnate ; pinnae very numerous, lanceolate, acuminate, 

 sessile, pinnatifid, the lower ones gradually reduced, the segments obliquely 

 acute, the lowest ones often elongated ; sori small, in a single marginal row 

 Polk County, Florida (J. D. Smith). 



5. A. unitum, var. glabrum, Mettenius. Stipe long and slender, 

 from a slender creeping rootstock ; frond rather rigid, smooth, ovate-lance- 

 olate, pinnate, l-2 long; pinna; lanceolate, piunatifid-lobed, the lobes 

 rounded; lower veins of contiguous lobes united; sori forming a continuous 

 zigzag intramargiual line. Boggy places, South Florida. 



* * Fronds thicker ; ultimate segments more or less serrate or toothed ; the lowest 



veins more than once forked. 



6. A. spinulosum, Swartz. Fronds ovate-oblong, thin, smooth ; bipin- 

 nate or below tripinnate ; pinna: oblong-lanceolate ; the lower ones broader, 

 triangular-ovate; ultimate segments oblong, or linear-oblong, closely set on a 

 narrowly winged partial rachis, variously incised or serrate with spinulose 

 teeth ; fruit-dots small ; iiulusium deciduous, sparingly glandular at the 

 margin. (A. intermedium, Muhl.) Shady woods in the upper districts. 

 Fronds l-2 long, 5' -9' wide, varying greatly in outline, and in the shape 

 of the segments. 



Var. dilatatum, Gray. Fronds wider in outline, of a rather firmer tex- 

 ture ; the pinna; fewer and set farther apart, the lowest pair largest, with the 

 2-3 lower basal pinnules elongated; segments larger and more distant; 

 fruit-dots larger; indusium smooth. Summits of the Black Mountains, 

 North Carolina (Rugel). Fronds l-2 long, 10' -16' wide. 



7. A. Goldianum, Hook. Frond broadly ovate, 2 -4 high; pinnae 

 oblong-lanceolate, deeply pinnatifid. 6' - 9' long, the segments oblong-linear, 

 slightly falcate, sharply serrulate ; fruit-dots small, arranged in a row on each 

 side of the midveiu ; indusium large with a narrow sinus. Low woodlands, 

 Tennessee, and northward. 



8. A. Floridanum, T>. C. Eaton. Fronds thickish, broadly lanceolate, 

 pinnate; lower pinna? sterile, triangular-lanceolate, deeply pinnatifid, with 

 closelv set oblong obtuse divisions; upper pinna; fertile, narrower and longer, 

 again pinnate, with oblong obtuse pinnules, distant on the narrowly winged 

 secondary rachis ; fruit-dots large, half-way between the midrib and margin ; 

 indusium round-reniform, smooth. (Nephrodium Floridanum, Hook.) Wet 

 woods, Florida to Louisiana. Fronds 1- 2 high, the sterile ones shorter, 

 growing in a crown from a thick and scaly rootstock. 



9. A. marginale, Swart/. Fronds evergreen, smooth, thickish and al- 

 most coriaceous, ovate-lanceolate, bipinnate; pinna; lanceolate from a broad 

 base ; pinnules oblong or linear-oblong, attached by a broad base to the nar- 

 rowly winged secondary rachis, entire or crenately toothed ; fruit-dots large, 



