624 FILICES. (FERNS.) 



SUBORDER IV. OSMUNDINE J5. Sporangia large, nearly sessile ow the 

 back or margins of the mostly contracted fertile fronds, two-valved, opening 

 vertically at the apex. Ring rudimentary or none. 

 25. OSMUNDA. Sporangia globular, covering the contracted fronds or portions of fronds. 



1. ACROSTICHUM, L. 



Sporangia entirely covering the lower surface of the upper pinnae. Veins 

 finely reticulated with oblong hexagonal meshes. Tall Ferns, with pinnate 

 frouds. 



1. A. aureum, L. Fronds coriaceous; pinna? short-stalked, lanceolate- 

 oblong, entire. Coast of South Florida. Fronds 4 -8 high, dark green, 

 shining. 



2. POLYPODIUM, L. POLYPODY. 



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

 Rootstocks creeping. Sterile and fertile fronds alike. 



1. PODYPODIUM proper. Veins free. 



1. P. VUlgare, L. Fronds evergreen, smooth on both sides, oblong, sim- 

 ply and deeply piuuatifid ; the divisions linear-oblong, obtuse, slightly toothed ; 

 fruit-dots large. Mossy rocks, etc. in shady woods in the upper districts of 

 Alabama, and northward. Fronds 4' - 10' high. 



o. p. Plumula, Willtl. 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. Leavenworth). Fronds 12'- 18' high, 18" -24" wide. 



3. P. pectinatum, L. Stipe erect from a stout rootstock, smoothish 

 (2' -6' long); frond l-2 long, broadly lanceolate, attenuate at each end, 

 deeply piiinatifid ; pinnae very numerous, alternate, linear-lanceolate, obtuse, 

 mostly entire ; sori in two rows. On trees, East Florida (Miss Reynolds, 

 Garber). 



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

 margin. Stipe and lower 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 in the lower districts. Rootstock chaffy, creeping. Fronds 3' - 8' 

 high. 



3. CAMPYLONEURUM, Presl. -Veins parallel, pinnate from the midrib: 

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

 veinlets proceeding from their angles. Fronds simple. 



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

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

 between the veins. South Florida. Frouds 1- 2 high. 





