This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Lycopodium clavatum L. Sp. PI. 1101. 1753.
Main stems prostrate, extensively creeping (3°-9°) along the ground, branching horizontally, with numerous very leafy ascending pinnately branched aerial stems; leaves crowded, many-ranked, linear, bristle-tipped, entire or denticulate, those of the main stems strongly denticulate; peduncles stout, 2 1/2- 4 1/2' long, channeled, with slender whorled or scattered denticulate bristle-tipped bracts, simple or several times forked near the summit; spikes linear-cylindric, the sporophyls deltoid-ovate, acuminate, or bristle-tipped, the margins scarious, erose.
In woods, Labrador to Alaska, south to North Carolina, Michigan and Washington. Also in Europe, Asia and tropical America. The spores of this species, and those of L. complanatum, furnish the inflammable power known as Lycopodium powder or vegetable sulphur, used in stage effects. Aug.-Oct. Called also running-moss. Foxtail. Buck's-horn. Buck's-grass. Staghorn-moss. Snake-moss. Wolf's-claws. Ground-pine. Toad's-tail. Lamb's-tails. Creeping-bur. Creeping Jennie. Coral-evergreen.
Lycopodium carolinianum L. Sp. PI. 1104. 1753.
Stems short, 1'-6' long, prostrate, pinnately branching, rooting below; leaves strongly dimorphic, those of the sides large, ovate-lanceolate, falcate, recurved, asymmetrical, acute, those of the upper side smaller, subulate from a broad base; peduncles 2'sV long, slender, with a few whorled or scattered subulate bracts; spikes 8-2' long, slender; sporophyls deltoid, acuminate, entire or somewhat erose.
In moist pine barrens, New Jersey to Florida and Louisiana near the coast.
Lycopodium complanatum L. Sp. PI. 1104. 1753.
Horizontal stems prostrate, wide-creeping, flattened above, sparingly branched, with numerous erect irregularly forked aerial stems, the branches of these broadly flattened, somewhat glaucous, 2-3-forked, the divisions few and somewhat apart or, more commonly, numerous, closer, and fan-like, leafy throughout, the leaves 4-ranked, minute and (excepting those of the under row) imbricate and strongly decurrent, those of the upper row narrow and incurved, of the lateral rows broad, with spreading tips, and of the under row minute, deltoid-cuspidate; peduncles slender, 1'- 5' long, bract-eate, rarely simple, usually once or twice dichotomous, each branch terminating in a slender cylindric spike about 9" long; sporophyls broadly ovate, acuminate.