The plants of Lycopsida have sporophytes, differentiated into roots, stem and true leaves. Leaves: The leaves are small and single-microphylls.The arrangement of leaves is spiral or opposite. Sporangia: The sporangia develop singly on the upper side of the sporophylls, which may or may not be arranged to form strobili. Ligule: In some lycopsida, such as Lycopodium, the leaves and sporophylls are without a ligule. In others, the ligule is present on the upper side of the leaves of sporophylls, near their base as in Selaginella. Homosporous or heterosporous sporophyte: The sporophyte may have sporangia of one kind as in Lycopodium or of two kinds i.e., micro sporangia and mega sporangia as in Selaginella. The sporophytes are thus referred to as "homosporous" and "heterosporous" respectively. This condition is called homospory and heterospory. Selaginella resembles seed producing plants because of its heterosporic condition. Gametophyte: The gametophyte of Lycopsida is mainly underground. Lycopsida are not mosses but are called club mosses/spike mosses because of their club/spike-shaped strobili and small leaves resembling mosses. These are also called ground pries because of their slight resemblance to the evergreen plants.
