 Cannel coal was accumulated in ponds and shallow lakes in peat-forming swamps and bogs of the Carboniferous age under oxygen-deficient conditions.Thus cannel coal seams are shallow and often found above other deposits, while the coal itself, being rich in oils, burns long, with a bright yellow flame and little ash.The modern Lycopodiopsida relatives of these lycopsids (scale trees), with their similar high oil content, high surface area spores, are the source of highly flammable lycopodium powder.