574 CRYPTOGAMIA FILICES 



Fertile stems appearing first, 6 to 9 inches high, simple, with a large ovoid-ob- 

 long terminal brownish spike (about 2 inches long, and half an inch to 2 thirds of 

 an inch in diameter) ; sheaths large, loose, or somewhat swelling above, with Ion* 

 acute teeth, striatc-ribbed, dark purplish-brown, whitish at base. Sterile stems 9 

 to 15 inches high, attenuated upwards, about 12-furrowed, sheathed at the joints, 

 with a verticil of slender articulated branches from the base of the sheaths ; 

 branches 4 or 3 to 8 or 9 inches long, ascending, 3 or 4-augled, simple (Sometimes 

 a little subdivided), scabrous, green,— each branch with its own sheath at base, 

 and sheathed at every articulation. 



J/ab. Moist grounds ; borders of thickets, &c. frequent Fr. April, May. 



j" \ Fertile stems at length throwing out verticil/ate branches, or 

 bearing the fructification at the same time with the branches. 



2. E. stlvaticux, L. Sterile and fertile stems both branched, the 

 branches compound, curved downwards; sheaths loose, deeply cleft into 

 membranous segments. Beck, Jiot. p. 446. 



Wood Eq,uisetum* 



Stems 9 to IS inches high, striate-sulcate, j »inted,— the joints invested with loose 

 sheaths which are divided at summit hit* several broad lanceolate membranous 

 tawny-ferruginous teeth (sometimes parted into 2 or 3 lance-oblong, segments); 

 fertile stems with veriicils of rather short, compound, 4-anglcd, divaricate, or de- 

 flected branches, from the base of the 3 or 4 uppermost sheaths, and terminating 

 in an oblong-ovoid brownish sjrike, about an inch long; sterile itetni usually 

 tailor and more slender, the joints nearly all furnished with verticils of tranches, 

 which are longer, and considerably subdivided. 



Ilab. Low grounds ; borders of woodlands : frequent. Ft. May. 



f f f Stems all fertile and simple, or branched only at base. 



3. E. htemaik, /,. Stems simple, naked, striate-sulcate, very rough, 

 bearing a terminal ovoid spike ; sheaths short, cy limine, whitish, with a 

 black ring at base and summit ; teeth lance-subulate, awned, deciduous. 

 Beck, hot. p. 446. 



Winter Eciuisetum. Vulgo — Scouring Rush. 



Stems 1 to 2 feet high, simple, terete, fistular, jointed, striate-sulcate, rough (the 

 ridges obtusely serrulate under a lens), pale cinereous-green, or glaucous (pur- 

 plish-black at base), terminating in an ovoid blackish strike about half an inch 

 lone; sheaths Z to 4 lines long, nearly cylindric, striate, whitish-cinereous, with 

 a purplish-black band at base, and at summit a ring of small blackish teeth, 

 which soon fall off, leaving the sheath truncate and entire. 



Hub. Margins of swamps: knolls, &c. frequent. FY. June. 



Obs. The cuticle of this plant abounds in silicious earth ; and its rough file- 

 like surface is well adapted to the scouring and polishing of hard wood, metals, 

 &C Three or four additional species are enumerated in the U. States ; and it it 

 not improbable that some of them may yet be found in this County. 



Order 3. Filices. 



Fer* ti:ibe. Floiccrless plants, with the fructification of only one kind upon the 

 same species. The a or capsules sometimes spiked, or raccmed, but generally 

 collected in Sori or clusters of Yarious shapes, upon the back or margin of the 



