BoTRYCHiuM. CLXIV. FILICES. C35 



loDg-, rather acute, entire ; some of the intermediate leaflets fertile. — A large 

 fern in low grounds. Fronds 2 — 3f high, light green, interrupted near the mid- 

 dle by 2 — 4 pairs of fertile leaflets, which are so much contracted in size as to 

 resemble dense, compound racemes, and densely covered with small reddish- 

 brown thecae. Stipe channeled, smooth above, chaffy at base. June. 



14. LYGODIUM. Swartz. 



Gr. XvywJej, flexible, slender; from the slender, climbing habit. 



Thecas sessile, arranged in 2-ranked spikelets issuing from the 

 margin of the frond, opening on the inner side from the base to the 

 summit; indusium a scale-like veil covering each theca. 



L. PALMATUM. Sw. Climbing Fern. 



Stem flexuous, climbing; fronds conjugate, palmate, 5-lobed, lobes entire, 

 obtuse ; spikelets oblong-linear, from the upper fronds, which are divided and 

 contracted into a compound spike. — This is one of the few ferns with climbing 

 stems, and the only one found in the U. S. Plant of a slender and delicate 

 structure, smooth. Stem 3 — 4f long. Stipes alternate on the stem, forked, 

 supporting a pair of fronds which are palmately divided into 5 — 9 segments. 

 Fertile fronds terminal, numerously subdivided into linear-oblong segments or 

 spikelets, with the fruit in 2 rows on the back. Mass. ! to Penn., &c. July. 



15. SCHIZiE A. Smith. 



Gr. <r^i^(j), to cut, cleave ; alluding to the many-cleft spikes. 



Spikes unilateral, flabelliform, aggregate ; thecoe roundish, radiate 

 at top, sessile, bursting laterally ; indusium continuous, formed of the 

 inflexed margins of the spikes. 



S. PLsiLLA. Pursh. (S. tortuosa. Mvhl.) 



Frond simple, linear, tortuous; spikes few, crowded at the top of a long, 

 slender stipe or scape. — A very delicate fern, found in the pine barrens, (Quaker 

 Bridge, N. J., also in Western N. Y. by Mr. l\motJuj Wcstmare > Fronds nu- 

 merous, caespitose, 2 — 3' long, ^ — I" wide. Fertile stipes several, 3 — 6' high, 

 filiform, with a lew short, unilateral spikelets at top arranged in 2 rows. 

 ThecaG somewhat turbinate, in 2 rows on the inner side of each spikelet. Aug. 



Tribe 3. OPHIOGLOSSE^.— Thecae 1-celled, adnate at base, subglpbose, 

 coriaceous, opaque, half-2-valved, not cellular, and destitutfe of a ring. 



IG. OPHIOGLOSSUM. 



Gr. o(l)ii, a serpent, yXoarcra, tongue; from the resemblance. 



Thecae roundish, opening transversely, connate, arranged in a 

 2-ranked, articulated spike. 



0. VULGATUM. Adder's Tongue. 



Frond simple, oblong-ovate, obtuse, closely reticulated; spike caulinc. — A 

 curious little plant in low grounds. Fronds solitary, 2 — 3' long, | as wide, 

 amplcxicaul, entire, .smooth, without a midvoin, situated upon the stem or stipe 

 a little below the middle. Stipe G — 10' high, terminating in a lance-linear, 

 compressed spike, 1 — 2' long, with the thecoe arranged in 2, clo.se, marginal 

 ranks. Thecoe opening outwards and horizontally, becoming lunate, distinct, 

 sliaw-colored. Vernation straight, not circinatc. June. 



17. BOTRYCHIUM. Swartz. 



Gr. PoTpvf, a cluster of irrnpcH ; fronj the rcHcmblaiice of the fructification. 



Thecno subglobose, 1-celled, 2-valved, distinct, coriaceous, smooth, 

 adnate to the compound rachis of a racemose panicle ; valves open- 

 iug transversely. 



1. B. NKGr.KCTUM, Wood. Meridcn Jlolryrhiinn. 



Stipe bearing the frond near the top] frond simply pinnate, very short, 

 with subentire or subpinnatifid segments ; spikes paniriilate. — A singular species, 

 54 



