FILICES. (ferns.) 599 



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

 tile frond distinct, contracted, liipinnatc, 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, pinnatelv decompound, bearing on its narrow divisions the- 

 large coriaceous, traasversely 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, ternatcly 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-pedunclcd ; rootstock short, erect ; roots fibrous, spreading horizontally. — 

 In sphagnous meadows and pastures, Tennessee, and northward. — Fronds 4'- 

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

 variable species. 



Var. crotalophoroides. 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- 

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

 6' high. 



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

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

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

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

 Fronds l'-4' high. 



