XXXViii INTRODUCTION. 



. Herbs. Stamens 6. Leaves 3 in a whorl. Flower single. TRILLIACE^;. 475 



Leaves alternate, sheathing. COMMELYNACE^, 497 



Stamens 3. Flowers perfect, solitary. Stem leafy. MAYACACE2E, 498 



Flowers perfect, capitate. Scape leafless. XYRIDACE^E, 499 



Stamens 3 or 4. Flowers monoecious, capitate. Scape leafless. 



ERIOCAULOXACELE, 502 

 * * Flowers glumaceous, i. e. with scale-like bracts, in place of proper floral envelopes. 



Bracts single. Sheaths closed. Fruit an achenium. CYPERACE.E, 504 



Bracts by pairs. Sheaths open. Fruit a caryopsis. GRAMINE.E, 545 



SERIES II. CRYPTOGAMOUS OR FLOWERLESS 

 PLANTS. 



Plants destitute of proper flowers, and producing, in place of 

 seeds, minute bodies (spores) which do not contain an embryo. 



CLASS m. ACROGENS. 



Plants with a distinct stem containing woody and vascular tissue, 

 growing from the apex only. 



Fructification borne on the under side of a peltate scale. EQUISETACK&, 585 



Fructification borne on the back or margins of the leaves (fronds). FILICES, 585 



Fructification borne in the axil of small leaves or bracts. LYCOPODIACE^:, 600 



Fructification borne at the base of the leaves. HYDROPTERIDES, 602 



