Some shoots are sterile while others are fertile, bearing at the apex the so-called fructification - a dense oval, oblong conical or cylindrical spike, consisting of a number of shortly-stalked peltate scales, each of which has attached to its under surface a circle of spore-cases (sporangia) which open by a longitudinal slit on their inner side.
The fructification appears in March and April, terminating in short unbranched stems. It is said to produce diarrhoea in such cattle as eat it.
The fructification in this species is cylindrical, and in that of E.
In this species the fructification is conical or lanceolate, and is found in April on short, stout, unbranched stems which have large loose sheaths.
Portions of the fructification may be preserved in small envelopes attached to the sheets.