374 



FERNS 



sporangial,.. 

 cone" 



internode •- 



furrows 



collar of... 

 teeth 



node- 



It is a hollow stem, with 

 joints, a mineral coating on 

 the outside of the stem, and 

 the branches in a circle 

 around each joint. The con- 

 ductive tissue in this plant 

 is arranged near the surface 

 of the stem (Figure 404). 



Selaginella is seldom seen 

 in northern latitudes, ex- 

 cept in greenhouses (Figure 

 405). 



264. Economic Importance. 

 — The fern group, like the 

 mosses, have little economic 

 importance. The spores of 

 the club mosses are used in 

 making certain kinds of fire- 

 works (especially those used 

 indoors) ; also in drug stores 

 to keep pills from sticking 

 together. The plant itself is used in Christmas decora- 

 tion. Horsetail, so named from its appearance, was 

 formerly cut, tied in bundles, and used for scouring, 

 and this accounts for its other name, the "scouring rush." 



265. The Formation of Coal. 

 — Ages ago ferns were more 

 numerous than they are now 

 and many of them grew to 

 be as large as our present 

 trees. Geologists tell us 

 that the climate was warmer 

 and more moist than it is 

 now, and conditions especially Figure 405. — Selaginella. 



Figure 404. — Horsetail. 



