SECOND GHANS EIVISION, 



CRYPTOGAMIA, OR FLOWERLESS PLANTS. 



Plants chiefly composed of cellular tissue, loilhout spiral vessels^ 



destitute of true flowers, and producing spores 



instead of seeds. 



CLASS V. ACROGENS. 



Flowerless plants with a proper stem or axis, often v/ith a vnscular 

 system composed chiefly of annular ducts, usually furni>he(l with 

 leaves. Grovvtei by the extension of the apex, without subsequent 

 increase in diameter. Spores with a proper integument, and 

 contained in a vessel analagous to an ovary, called tueca or 



SPORANGIUM. 



ORDKR CLXII. EQUiSETACE/E. TAc Scouring nu,k Tribe. 



InfloTesreiire{hy analogy) a dense, cylinclric, terminal spike oi stroliile. 



Scales t>i' the siruliile peltate, liexagnnal. sul)verlieillate. 



Tnerfp4—7, attached to tlie undei suriiue cit the scales, with lateral deliiscence. 



SpoTff numerous, globose, surrounded by minute prranules. [in a spiral manner. 



EUiters, bodies ol' unknown use, consisting of 4 elastic, clavaie filaments involving the spore* 



Plant lejifless, simple or with verlicillate branches. 



Stem striate-sukale, joijiied. fistuUir between, and separable at, the joints. 



Shealk^ dentate, crowningthe summit ol'each inlerjiode. 



An order consisting at present ol a single genus, growing in wet grounds, on river banks, 

 and borders oC woods, thrtmihout mist countries. 'I"he llquisetaccre aijonrid In the (iissil 

 remains oi' coal measures with other (""ryptogaml.i, as Fiycopodiace.x and Filii-es.iudicatiji? 

 that lliese plants were once ol gigantic dimensions, and I'ormed a large part of the original 

 flora otour globe. 



Prnperiies. They abound insilex, and hence are used by cabinet-makers, comb-makers, 

 &c., in polishing their work. 



EQUIS K'TUM. 

 Clinractci- IJic sanne ;is that ofllio order. 



1. E. iivkm'.\i,f.. Scouring Rush. 



5' cms all siiiiple, erect, very rough, each bearini a terminal, ovoid spike; 

 sheiith ctnerous white, bhici< at the base and siiiiimit, sliorl, with subulate, 

 awned and deciduous teetii. Very nolii:eable in wet, shady srrounds, and by 

 brook sides. Stems about 2 feet iiijrh, often 2 or more united at l)ase frotn 

 the same root. Sheaths 1 — 2 lines lonir, I — 2^ inches ajiart. the white ring 

 mucii broader than the black, .at length entire from the fallinir of the teeth. 

 The roughness of the cuticle is owing to the silex in its composition. Jn. 



