XIII LYCOPODINEJE 485 



leaves, though usually nuuiercms, are simple in structure and 

 generally small. The genera are all homosporous except 

 Selagiuclla, which is very markedly heterosporous, and has the 

 gametophyte very much reduced and projecting hut little l)e- 

 yond the spore wall. 



C LAS SI PICA TION 

 Order I. Lycopodiales 



A. Homosporecu 



T. Roots always present ; sporangia alike, simple, in the 

 axils of more or less modified leaves, which may form a distinct 

 strohilus, or may he hut little different from the ordinary ones 

 both in form and position ; prothallia either green or colourless, 

 monoecious. 



Family I. Lycopodiace^ 



Genera 2. — (i) Lycopodiiun; {2) Phylloglossnin 



11. Roots absent ; vegetative leaves much reduced or well 

 developed ; sporophylls petiolate, bilobed ; sporangia pluriloc- 

 ular ; gametophyte unknown. 



Family II. Psilotace.-e 

 Genera 2. — (/) Psilofuiu; (2) Tiucsipfcris 



B. Heterosporeco 



Characters those of Family I., but spores always of two 

 kinds. 



Family III. Selaginellace^ 

 Genns i. Sela^inclla 



'^ 



THE LYCOPODIACE^ 

 The Gametophyte 



The Lycopodiace?e include the two genera Lycopodium 

 and Phylloglossitm, the latter with a single species, P. Dniiii- 

 mondii. The gametophyte is known in a number of species 

 of Lycopodiiun , and recently (Thomas (i)), has also been 



