INTRODUCTION lxXlX 



Tribe II.— GLUMACEiE. 



Flowers destitute of true calyx and corolla, but enveloped in imbricated 



br acted. 



Leaf sheaths entire. Embryo undivided, included within the t .,..., , ■____ . __ _, 



albumen. Stein angular S 



Leafsheaths slit. Embryo lenticular, on the outside of the al- ) 9 g. r; RAMINEjE 



bumen, with a naked plumula. Stem cylindrical J 



Class tt.— CELLULAEES. 



Neither stamens, pistils, flowers, nor spiral vessels. 



* FlLICOlDEiE. 



A distinct axis and vascular system. 



Reproductive organs in terminal cones - - 263. Equisetaceje. 



Reproductive organs dorsal, in theca; or naked - 264. Eilices. 



Reproductive organs in axillary theca; - - 265. Lycopodjace.e. 



Reproductive organs in theca; enclosed within indehiscent ) 2„6 Mahsileaceje 

 involucra ----■-• y " 



** MuscOIDEjE. 



A distinct axis, but no vascular system. 



Theca closed by an operculum - - 267. Musci. 



Theca dehiscing without an operculum - 263. Hepatioe. 



Theca indehiscent, deciduous. Branches leafless and verticillate 269. CHAaACE.E. 



*** APHYLLiE. 



Neither distinct axis nor vascular system. 



Aerial; always growing exposed to the air. 



Sporules lying in superficial receptacles - 270. Lichenes. 



Sporules internal - - - - 271. Fungi. ' 



Aquatic ; always growing under water - - 272. AlgjE. 



