FILICES. (FERNS.) 599 



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

 tile frond distinct, contracted, bipinnate, very woolly, densely covered with cin- 

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

 Low grounds, Florida, and northward. Fronds l-3 high. 



22. BOTRYCHIUM, Swartz. MOONWORT. 



Fronds mostly solitary, erect from a root of thickened fleshy fibres ; the termi- 

 nal branch fertile, pinnately decompound, bearing on its narrow divisions the 

 large coriaceous, transversely 2-valved sporangia ; the lateral branch sterile, with 

 forking free veins. 



1. B. Virginicum, Swartz. Stem tall; sterile part of the frond sessile, 

 broadly triangular, ternately 3 - 4-pinnate ; ultimate segments oblong-lanceolate, 

 thin and delicate, toothed and incised; fertile part long-stalked, 2-3-pinnate. 

 Shady woods, Florida, and northward. Fronds 4' -2 high. 



2. B. lunarioides, Swartz. Stem low ; sterile part of the frond mostly 

 long-stalked, broadly triangular, 2 - 4-pinnate ; ultimate segments of a thick and 

 fleshy texture, roundish, ovate, oblong or lanceolate, entire, toothed, incised, or 

 even dissected into very narrow lobes ; fertile part taller than the sterile, ovate, 

 2-3-pinnate. (B. fumarioides, Willd. B. obliquum and B. dissectum, Muhl.) 

 Low shady woods and pastures, rarely in open pine-barrens, Florida, and 

 northward. Fronds 3' -10' high, the succulent stem divided down to the sur- 

 face of the ground, or even lower. 



23. OPHIOGLOSSUM, L. ADDER'S-TONGUE. 



Fronds mostly solitary, with short and often thickened rootstocks, and fleshy 

 fibrous roots ; sporangia large, coriaceous, opening transversely, connate, arranged 

 in compact simple 2-ranked spikes, proceeding variously from the mostly simple 

 sterile part of the frond. Veins reticulated. 



1. O. VUlgatum, L. Sterile part of the frond ovate or oblong-oval, ob- 

 tuse, sessile near the middle of the stem, without a midrib ; fertile spike terminal, 

 long-peduncled ; rootstock short, erect ; roots fibrous, spreading horizontally. 

 Insphagnous meadows and pastures, Tennessee, and northward. Fronds 4'- 

 10' high. The following are probably but forms of this widely diffused and 

 variable species. 



Var. crotalophoroid.es. Smaller ; sterile part of the frond near the base 

 of the stem, ovate, abruptly contracted at the base and slightly petioled ; spike 

 short and thick ; rootstock bulbous; roots slender. (0. crotalophoroides, Wal- 

 ler. 0. bulbosum, Michx.) -Low grounds, Florida to Louisiana. Fronds 3' - 

 6' high. 



Var. nudicaule. Small, sterile part of the frond near the base of the stem, 

 ovate or oblong, acute, narrowed into a short petiole ; spike linear acuminate ; 

 rootstock bulbous; roots coarse. (O. nudicaule, L. f. 0. ellipticum, Hook. $* 

 Grev.) Low sandy places or occasionally in dry soil, Florida and Georgia. 

 Fronds l'-4' high. 



