PLANTS. 143 



leaves, or roots, and consisting wholl}' of cellular tissue ; as, 



(a) Algse, or Seaweeds; (b) Lichens. 



2. An'ogens, having short stems, usually leafy, and roots, 

 and consisting wholly of cellular tissue ; as, (a) Ilejxiticse, 

 or Jiiverworts ; (b) Mosses. 



3. Ac'rogens, having stems, leaves, and roots, and consisting, 

 in part, of vascular tissue ; as, (a) Ferns, or Brakes ; (b) 

 Lj/copodia, or the Ground-pine tribe ; (c) Uquiseta, or the 

 Horse-tail tribe. 



2. Phen'ogams (called also Phanerogams). — Plants having 

 distinct flowers and true seed. 



1. Gr-u'NOSPERMS, having the flower exceedingly simple, and 

 the seed naked, the latter being ordinarily on the inner sur- 

 face of the scales of cones. They are exogenous, and con- 

 sequently have bark and rings of annual growth, but are 

 without spiral ducts; as, (a) Conifers, or the Pine tribe; 



(b) Cycads, or plants related to the Cycads and Zamia ; 



(c) Sigillarids, extinct species of the later Paleozoic era in 

 geology. 



2. En'dogens (called also Monocotyledons), having regular 

 flowers and covered seeds. They are endogenous, and 

 therefore without bark or rings of annual growth, as 

 Palms, the Rattan, Grasses, Indian Corn, the Lily, and 

 the like. 



3. An'giosperms (called also Dicotyledons), having regular 

 flowers and covered seeds. They are exogenous, and there- 

 fore have bark and rings of growth as in the Gymnosperms, 

 and the wood consists, in part, of spiral ducts ; as the 

 Maple, Elm, Apple, llosc, and the like. 



The Gymnosperms and Angiosperms make up the division of 

 plants called Exogens. 



ELEMENTAEY OKGANS OF FRUCTIFICATION. 



Ca'lyx. — The outer or lower part of the flower, the divisions of 

 which are called sepals. 



subdivisions of the calyx. 

 Per'ianth. Am'ent. 



Involu'cre. Calyp'tre. 



Spathe. Vol'va. 



Glume. 



