SYNOPTICAL KEY TO THE OIlDEllS. ^V 



Skiues II. CRYPTOGAMOUS oil FLOWERLESS PLANTS. Flowers without 

 staiiKJiis or pistils, in Iniit jjioduciiif^ spores iiisteail of seeds. 



Class III. ACROGENOUS PLANTS. Growing from the apex of a distinct axis, 

 mostly with distinct leaves. 



Subclass I. VASCULAR ACROGENS. Plants willi both woody and cellular tissue: 

 reproductive organs of one or both sexes produced upon a prothalhis devehiped fr.mi 

 the spore. 



Division 1. ISOSPOHOUS VASCULAR ENDOGENS. Spores only of one kind, the pro. 

 tlialius l)earing organs of both sexes. 



120. Equisetaceae, p. 'Vl'.K Cylindric jointed hollow-stennned plants, with toothed slieaths. 



Fnictiliriition in a tciniinal spike. 



121. Ophioglossaceae, p. 3:il. Fronds often fern-like, erect in vernation. Sporangia glolwsc, 



coriaceous, in special sjiikcs or panicles. 



122. Filices, p. 3:32. Ferns, with fronds circiiiatc in vernation, bearing the fructification on the 



under surface or beneath the margin. 



Division II. II FTKHOSPOHOPS VASCULAR ACHOOKNS. Spores of two kinds, one pro- 

 ducing a prothallus with aiciicgonia, the other smaller and containing antherizoids. 



123. Selaginelleae, p. 349. The two kinds of spores borne separately upon the upper side of the 



base of linear grass-like radical leaves or in the axils of small leaves arranged in 4 ranks 

 U|)on a stem. 



124. Marsiliaceae, p. Sol. Spores of both kinds together in jieduncled capsules borne upon a 



rhizome. Leaves liliform or pedately (piadiifoliolatc. In mud. 

 12'). Salviniaceae, ]>. 352. Small floating jilants, the si)ores borne in sejiarate capsules at the 

 base of the frond. 



Subclass II. CELLULAR ACROGENS. Plants with cellular tissue only : reproduc- 

 tive organs borne upon the stem or branches. 

 A. Capsules mostly opening by a lid, containing numerous spores without spiral fibres {cln(crs). 



126. MuBci, p. 3ri3. Branches not regularly fascicled along the stem. Tissue of the leaves 



homogeneous. Spores of one kind. 



127. Sphagnaceae, p. 421. Branches regularly fascicled. Tissue formed of colorless cells and 



intermediate green linear ducts. Spores of two kinds. Pale flaccid bog plants. 



B. Cnpsule not opening by a lid : spores mixed with elaters. 



128. Hepaticae. Stems procumbent, leafy with alternate or distichous leaves, or thalloid. 

 C. Sporangium consisting of a single large spore surrouiukHl by spirally arranged tulx-s. 



129. Characeae. Submerged acpiatics, with whorlcd branches, consisting of tubular cells 



placed end to end. 



Class IV. THALLOGENS. Growth chiefly periplierical and horizontal, without 

 definite axis, mostly without leaves, and composed wdiolly of cellular tissue : spores 

 not developing a prothallus. [Added here to complete the Series.] 



130. Lichenes. Not parasitic, on exposed surfaces, prostrate and crustaceous or fiondoso, or 



erect, containing chloroi)liyllose granules. Reproductive organs of two kinds, apolhccia 

 and sprrmoqonia. 



131. Fungi. Parasitic, wholly without chlorophyll, the orgnnsof vegetation (mi/celiuvi) uiostly 



subterranean or concealed, the reproductive very various in form and structure. 



132. Algae. Aquatic, mostly submeif;e<l, not parasitic, always coiitainiiig chlorophyll and 



usually highly colored. Reproductive organs very various. 



