SECOND GRAND DIVISION, 
CRYPTOGAMIA, OR FLOWERLESS PLANTS. 
Plants chiefly composed of cellular tissue, without spiral vessels, des- 
titute of true flowers, and producing SPORES ; 
instead of seeds. 
CLASS V. ACROGENS.. | 
Flowerless plants with a proper stem or axis, often with a vaseu- 
lar system composed chiefly of annular ducts, usually furnished with 
leaves. Growru by the extension of the apex, without subsequent 
increase in diameter. Spores with a proper integument, and. con- 
tained in a vessel analogous to an ovary, called THECA or SPORANGIUM, 
Orver CLXIL EQUISETACE #.—Horsetans, 
Plant \eafless, simple or with verticillate branches. ‘ 
Stem striate-sulcate, jointed, fistular between, and separable at, the joints. 
Sheaths dentate, crowning the summit of each internode. _ : 
Inflorescence (by analogy) a dense, cylindric, terminal spike or strobile. 
Scales of the strobile pe}tate, hexagonal, subyerticillate. _. ; 
Thece 4—7, attached to the under surface of the scales, with lateral dehiscence. ; 
Boas numerous, globose, surrounded by minute granules. si as '_[{manner. 
Elaters, bodies of unknown use, consisting of 4,elastic, clavate filaments involving the spores.in a spiral}. 
_ An order consisting at present of a single genus, growing in wet grounds, on river banks, and borders 
of woods, throughout most countries. The Equisetacee abound in the fossil remains of coal measures. 
with other Cryptogamia, as Lycopodiacee and Filices, indicating that these plants were once of gigantic 
dimensions, and formed a large part of the original flora of our globe. Speciesabout 10. 
Properties.—They abound in silex, and hence are used by cabinet-makers, comb-makers, &c., inpolish- 
ing their work. 
EQUISETUM. 
Lat. equus, a horse, seta, hair; perhaps alluding to the general resemblance, 
Character the same as that of the order. 
1. E. HYEMALE. Scouring Rush. 
Sts. all simple, erect, very rough, each bearing a terminal, ovoid spike ; 
sheath cinerous white, black at the base and summit, short, with subulate, 
awned and deciduous teeth.—Verv noticeable in wet, shady grounds, and by 
brooksides. Stems about 2f high, often 2 or more united at base from the same 
root. Shéaths 2—3” long, 1—23/ apart, the white ring much broader than the 
black, at length entire from the falling off of the teeth. The roughness.of: the: 
“ 
cuticle is owing to the silex in its composition. June. 
2. E. aRvENSE. Feld Horsetail. 
Fertile sts. erect, simple, sterile with simple, quadrangular branches, de- 
cumbent at base.—Low grounds, Free States and Brit. Am. Fertile stems first 
appearing, 6—8’ high, with 3—5 joints surmounted by large, inflated sheaths cut: 
into long, dark brown teeth. Spike oblong, 4—2/ long, Sterile stems rather 
taller than the fertile; remaining through the season, after these have decayed. 
At each joint is a whorl of simple, rough, ascending branches; issuing from the. 
base of the sheaths, their joints also sheathed. April. “Staee 
3. EK. syivaticum. Wood Horsetail. A 
Sterile and fertile sts. with compound, rough, deflexed, angular branches.— 
Grows in woods and low grounds, Free States and Brit. Am. Stems: 9—16/ 
