CLXIV. FILICES. 637 



small, creeping, moss-like species, in wet, rocky shades, U. S., not common. 

 Stem a few inclies long, filiform. Leaves less than a line in length. Spikes 

 leafy, scarcely distinguishable Irom the branches. July, Aug. 

 * * * Spikes indhtinguishablc from the branches. 



12. L. LUciDULUM. Michx. Shining Club Moss. 



St. ascending, dichotoraously divided ; Ivs. in 8 rows, linear-lanceolate, den- 

 ticulate, shining, spreadmg, or a "little reflexed; th£ccB in the axils of leaves not 

 changed nor crowded into a spike.— In wet woods, U. S. and Can. The foliage 

 of this species is dark green and shining, more ample than is common to the 

 genus. Stems 8—16' long, nearly erect. Leaves 3—5" long, distmctly 

 serrate. Thecse hemispherical or reniform, in the axils of the leaves near the 

 top of the stem. Jl. 



13. L. SELAGO. (L. recurvum. WiUd.) Fir Chd> Moss. 



St. erect, dichotomously and fastigiately branched ; Ivs. scattered, imbri- 

 cate, lance-linear, entire, rigid and pungent, but awnless.— A smaller species 

 than the last, found on the summits of the White Mts. Stems 4—8' high, 

 densely clothed with stifi", shining, spreading leaves arranged somewhat in 8 

 rows and 2 — 3" in length. Thecse axillary. Aug. 

 ISOETES. 

 Gr. laos, equal, eroi, the year ; from its being evergreen. 



Thecse membranaceous, oblong, cordate, 1 -celled, immersed in the 

 dilated base of the frond; spores subglobose, slightly angular, 

 attached to numerous filiform receptacles. 



I. LACusTRis 1 (I. riparia. Engelman.) Quill-wort. 



Leaves csespitose, subulate, semiterete, dilated and imbricated at base. — A 

 curious aquatic, in water at or near the margin of ponds and rivers, N. Eng! 

 and Mid. States, often wholly submersed ! Leaves or Ironds numerous, tufted and 

 simple, 3—10' long, somewhat spreading, containing numerous cells divided both 

 by longitudinal and transverse partitions. Thecse whitish, imbedded in cor- 

 responding cavities in the bases of the fronds, traversed within by many threads 

 to which the numerous, small, white, granular .spores are attached. Aug. — Our 

 plant differs slightly from the European (with which I have compared it), but 1 

 think not specifically. 



Order CLXIV. FILICES.— Ferns. 



gjewi a perennial, creeping, horizontal rhizoma, or sometimes erect and arborescent. . . [nation. 



Fronds (fruit-bearing leaves) variously divided, rarely entire, with forked vems, mostly circmate m vet- 

 Infiorescence occupyiiiff the back or margin of the fronds (leaves) arising from the veins. 

 Theca or sporangia ofone kind only in the same plant, 1-celled, dehiscing irregularly. 

 Son, somewhat regular collections of theca;; or the theca! are isolated and scattered. , .. <• , 



JndvMum, a scale investing each sonis ; or the sori are covered with the revolute margin of the trona, 

 or they are naked. 



Genera 192, species 2040. A large and interesting order of flowerless plants, distinguished for their ele- 

 gant plume-like foliage. They are usually a few inches to a few feet high, but some ot the tropical spe- 

 cies, as the Cyathea; of both Indies, are 15—25 feet high, vieing with the pahns in size and beauty. 



Prraer^fes.— Generally mucilaginous and mildly astringent, hence considered pectoral. Aspidiumand 

 Pteris are anthelmintic. Osmunda regalis has been successfully admmistered tor the rickets. 



Observation.— The fructification of the ferns, with its various appendages, is too minute to be well 

 observed by the naked eve ; but an examination of it with the aid of a good lens, cannot taU to be inter- 

 estine and satisfactory, "in regard to the localities of the ferns, it should heie be remarked, that the spe- 

 cies respectively are more generaUy disseminated throughout the States represented by this flora, and 

 also British America, than are the species of the Pha-nogamia. They are, however, tar more common 

 in the hard, mountainous or rocky soils of the East than in the fertile regions ot the ^V est. It seems, 

 therefore, unnecessary to malce particular mention of the geographical range of the more common species. 

 Conspectus of the Genera. 

 * Fertile leaflets or fronds contracted into the form of a panicle or spike. 



(Stipes 4 angular Omclea. 11 



( the fert. fronds < smoothish, \ deeply grooved within. Strutliiopteris. 12 



< distinct. . . ( Stipes clothed with reddish wool . Osnnmda. 13 



("Fronds ma- ^divided,? each one partly fertile <^nunda. 13 



ny, radical, ( entire and narrowly hnear kchizOM. 15 



fern 1 S entire. Scape spicate Ophwglqssmn. 16 



erect. I Frond solitary, on a scape, < divided. Scape paniculate Botrychtrimi. 17 



Fem climbing, stem long and slender LygoaiU7n. 11 



53* 



