FIG. 305. Equisetum arvense, a common horsetail: 1, three fertile shoots rising from 
the dorsiventral stem, showing the cycles of coalesced scale-leaves at the joints 
and the terminal strobili with numerous sporophylls, that at a being mature; 2, 
a sterile shoot from the same stem, showing branching; 3, a single peltate sporo- 
phyll bearing sporangia; U, view of sporophyll from beneath, showing dehiscence 
of sporangia; 5, 6, 7, spores, showing the unwinding of the outer coat, which aids 
in dispersal. After WOSSIDLO. 
