542 



CEYPTOGAMOUS OR FLOWEELESS PLANTS. 



Vegetables devoid of manifest staminate and pistillate 

 flowers, and reproduced from spores which contain no distinct 

 embryo. 



DIVISION LVASCULARES on ACROGEN& 



Stem when present filled with vascular tissue. Plants re- 

 produced from minute spores, which in germination form a 

 membranous bulbiform or filamentous body termed the pro- 

 thallus, upon which the reproductive organs are developed, 

 giving rise to new individuals. 



ORDER I. PILICES. 



Herbaceous or shrubby plants, sometimes attaining the 

 dimensions of trees in the tropics and the temperate regions 

 of the southern hemisphere. Stem when erect simple, but 

 as a creeping rhizome often branched. Leaves (here termed 

 fronds) tufted or alternate, simple or more or less divided ; 

 vernation circinate, or rarely straight as in the Ophioglossew. 

 Petiole or stipes continuous or jointed, rachis or midrib often 

 grooved above. Fructification consisting of minute capsules 

 of spores borne in clusters (sori) on the under side or edge of 

 the fronds, or sometimes on separate fronds. Sori naked, or 

 covered with an orbicular peltate reniform linear bivalved or 

 urceolate involucre or indusium. Capsules or spore-cases 

 sessile or stipitate, frequently intermixed with bristles, or 

 imperfect spore-cases. Ferns inhabit nearly all climes, but 

 they are rare in very cold and arid regions, and attain their 

 greatest development in tropical and temperate countries pos- 

 sessing a humid atmosphere. There is a wide divergence of 

 opinion amongst pteridologists as to the number of genera and 



