The life cycle of the clubmoss consists of alternating generations of familiar spore-producing plants and inconspicuous underground gametophytes. Clubmoss sporophytes often exhibit creeping or prostate stems, sometimes located underground, but certain species possess erect stems. The stems are almost always heavily branched and thickly covered with small, needle- or scale-like green leaves. The spore-bearing leaves of clubmosses are typically organized into strobili, but a few members of the genus Lycopodium, including the shining clubmoss (L. lucidulum) native to North America, bear sporangia at the bases of leaves that are spread out rather than clumped together into cone-like structures. Clubmoss sporangia contain a single type of spore, which when released may quickly develop into a subterranean prothallium.