588 FILICF.S. (KKUNS.) 



1. ACROSTICHUM, L. 



Sporangia entirely covering tiie lower surface of the upper pinnaj. Veins 

 finely reticulated with oblong hexagonal nicshes. — Tall Ferns, with pinnate 

 fronds. 



1. A. aureum, L- Fronds coriaceous; pinna: short-stalked, lanceolntc- 

 ol)long, entire. — Coast of South Florida. — Fronds 4° - 8° high, dark green, 

 shining. 



2. POLYPODIXJM, L. roLYPODT. 



Fruit-dots round, naked, mostly at the ends of the free or reticulated veins. — 

 Eootstocks creeping. Sterile and fertile fronds alike. 



(, 1. POLYPODIUM Proper. — Veins free. 



1. P. VUlgare, L. Fronds evergreen, smooth on hoth sides, oblong, 

 simply and deeply pinnatifid ; the divisions linear-ohlong, ol)tusc, slightly 

 toothed ; fruit-dots large. — Mossy rocks, &c., in shady woods, in the upper 

 districts of Alabama, and northward. — Fronds 4'- 10' high. 



2. P. Plumula, Willd. Fronds linear-lanceolate, narrowed at both ends, 

 pinnatifid to the black and somewhat chaffy midrib; the divisions very numer- 

 ous, narrowly linear, entire, wider at the base ; fruit-dots small. — Tampa Bay, 

 Dr. Leavemrorl/i. — Yromh 12' -18' high, 18"- 24" wide. 



3. P. hexagonopterum, Michx. Fronds annual, broadly triangular, 

 bipinnatifid ; pinnae lanceolate, acuminate, spreading, the lower pair erect; pin- 

 nules oblong, mostly obtuse, crenately toothed or entire ; fruit-dots numerous, 

 minute. — Shady woods, Florida to Mississippi, westward and northward — 

 A foot or more high from an elongated creeping rootstock. Pinna; dccurrent, 

 forming irregular hexagonal wings on the rachis. 



§ 2. MARGINARIA, Bory. — Veins obscure, sometimes reticulating near the 

 margin. Stipe and loicer surface of the frond covered with chaffy scales. 



4. P. incanum, Swartz. Fronds evergreen, coriaceous, beneath thickly 

 beset with peltate chaffy scales, smooth and green above, pinnately parted ; the 

 divisions oblong, obtuse, entire ; fruit-dots near the margin. — On trunks of trees, 

 Florida to Mississippi, westward and northward. — Rootstock chaffy, creeping. 

 Fronds 3' -8' high. 



§ 3. CAMPYLONEURUM, Presl. — TVns parallel, pinnate from the midrib: 

 veinlets reticulated, forming a series of parallel angular arcs with short veinlets pro- 

 ceeding from their angles. Fronds simple. 



5. P. Phyllitidis, L. Fronds linear-lanceolate, entire, acuminate, of a 

 thin ehartaceous texture, semi-pellucid ; fruit-dots rather large, in two rows 

 between the veins. — South Florida. — Fronds 10-2° high. 



^ 4. PHLEBODIUM, R.Bv. —Veins pinnate from the midrib, furcate: veinlets 

 reticulated in mostly elongated meshes. Fruit-dots large, commonly at the extremities 

 of two converging veinlets, 



6. P. aureum, L. Fronds smooth and glaucous, broadly ovate, pinnately 



