212 
THE BRITISH CLUB-MOSSES. 
Genus XX. LYCOPODIUM, or CLUB MOSS. 
The Lycopodiums^ commonly called Club-mosses, are 
moss -like plants, mostly of creeping or decumbent habit ; 
with slender fork-branched stems, consisting of spiral 
vessels and tubular ducts running longitudinally among 
the cellular tissue ; they are throughout their whole length 
clothed with leaves, so placed as to overlie each other like 
the tiling of a roof. The fructification is produced in the 
axils of the leaves, and is in most of the species confined 
to the apices of the branches, where it forms a cone-like 
head. 
The organs of reproduction at once distinguish the 
Club- mosses from all other plants. They consist, in the 
true Lycopodiums^ of kidney-shaped spore-cases, contain- 
ing minute powdery or granular spores, which, by reason 
of lateral pressure, acquire the form of irregular polygons. 
