Lycopodium powder

Lycopodium powder is a yellow-tan dust-like powder historically used as a flash powder. It is composed of the dry spores of clubmoss plants, various fern relatives principally in the genera Lycopodium and Diphasiastrum. When mixed with air, the spores are highly flammable because of their high fat content and their large surface area per unit of volume — a single spore's diameter is about 33 micrometers (μm). Preferred source species are Lycopodium clavatum (wolf's-foot clubmoss) and Diphasiastrum digitatum (common groundcedar) because these widespread and often locally abundant species are both prolific in their spore production and easy to collect.