ID by Colin.
Was excited to find this species. Not very good with ferns or their allies but I think this is L. clavatum.
Lycopodiopsida is a class of plants often loosely grouped as the fern allies. Traditionally the group included not only the clubmosses and firmosses, but also the spikemosses (Selaginella and relatives) and the quillworts (Isoetes and relatives). However, the latter are now usually separated off into a separate class, Isoetopsida.