636 OPHIOGLOSSACE^E. (ADDER'S TONGUE FAMILY.) 



1. A. adiantifolia, Swartz. Fronds sparingly pubescent, erect on a 

 slender stipe ; the two lower branches elongated, pinnately decompound, fer- 

 tile; sterile part of the frond deltoid-ovate, 2 - 3-pinnate ; ultimate segments 

 obovate, cuueate, entire or lobed, striate above with numerous flabellate veins. 

 - Key West, etc., South Florida. Fronds 6' - 12' high, rather rigid. Root- 

 stock creeping, slender, covered with a black tomeutum. 



25. OSMUNDA, L. FLOWERING FERN. 



Sporangia globular, short-pedicelled, having an incomplete transverse ring, 

 represented by a few parallel stria} near the apex, opening by a vertical chink 

 into two nearly equal valves, pauiculately arranged on contracted parts of the 

 frond or on separate fronds. Fronds tall, erect, several from a stout root- 

 stock, 1 - 2-piuuate. Veins forking, free. 



* Fronds lipinnate, fertile at the top: sterile pinnce few. 



1. O. regalis, L. Fronds ovate, smooth ; sterile pinnae distant ; the finely 

 serrulate pinnules distinct, oblong-lanceolate, cordate or truncate at the nearly 

 sessile base, sometimes auricled at the lower side of the base; the upper pinnae 

 erect, panicled and thickly covered with light brown sporangia. Swamps, 

 Florida, and northward. Fronds l-5high; pinnules 1'- 2' long, 3" -4" 

 wide. 



# * Sterile fronds pinnate : the pinnce numerous, deeply pinnatifid, with oblonq 



entire segments. 



2. O. Claytoniana, L. Fronds broadly lanceolate, woolly when young, 

 at length nearly smooth ; sterile pinna? sessile, oblong-lanceolate, deeply piu- 

 natifid ; the segments crowded ; fertile pinnae few, between the middle and the 

 base of the frond, contracted, the sporangia deepening in color as the sterile 

 pinnae expand. (< ). interrnpta, Michx.) Low grounds in the upper districts, 

 and northward. Fronds 2 -3 high. 



3. O. Cinnamomea, L Sterile fronds covered with rusty wool when 

 young, at length smooth ; pinnae sessile, lanceolate ; segments broadly oblong, 

 obtuse ; the lower basal ones in large fronds often elongated and pinnatifid ; 

 fertile frond distinct, contracted, bipinnate, very woolly, densely covered with 

 cinnamon-colored sporangia, withering before the sterile fronds are expanded. 

 Low grounds, common. Fronds l-3 high. 



ORDER 165. OPHIOGLOSSACEJE. (ADDER'S TONGUE 



FAMILY.) 



Sporangia very large, sessile, spiked or panicled, coriaceous, not 

 reticulated, on narrow divisions of the frond, destitute of a ring, 

 transversely two-valved. Fronds not circinate in vernation. 



Synopsis. 



1. BOTRYCHIUM. Sporangia in panicled spikes. Sterile part of the frond pinnately 



divided. 



2. OPHIOGLOSSUM. Sporangia in a simple spike. Sterile part of the frond simple (except 



No. 4). 





