32 ANALYTICAL KEY. 



Cm Glumaceous Division. Flowers destitute of any -proper perianth, except 

 sometimes small scales or bristles, but covered by glumes, i. e. husk-like or scale- 

 like bracts. 



Glume a single scale-like bract with a flower in its axil. . Cyperace^e, 550 

 Glumes in pairs, of two sorts Gramine^, 602 



Series II. CRYPTOGAMOUS or FLOWERLESS PLANTS : 

 those destitute of stamens and pistils, in fructification producing spores 

 instead of seeds. 



Class III. ACROGENOUS PLANTS. 

 Plants with a stem containing woody tissue and vessels, as does the 

 foliage when there is any (in the form of veins). 



Fructification of several spore-cases borne on the under 



side of the shield-shaped stalked scales of a terminal 



spike or cone. Leaves none, except a whorl of teeth 



at each joint of the stem. Equisetace^;, 653 



Fructification borne on the leaves (fronds), commonly on 



their hacks or margins Filices, 655 



Fructification of spore-cases in the axil of simple leaves 



or bracts. Lycopodiace^e, 672 



Fructification on the branches or petioles. - - Hydbopxf rides, 677 



