Cordyceps militaris (L. ex St. Amans) Link. Scarlet Caterpillar Club. Fruit body up to 7cm high, cylindrical or club-shaped; bright orange-red; the slightly swollen fertile head has a finely roughened surface and tapers into a smooth, paler, wavy stem. Asci very long, about 4µ wide. Spores threadlike, breaking into barrel-shaped part-spores, 3.5-6 x 1-1.5µ. Habitat singly or numerously on larvae and pupae of butterflies and moths. Quite common. Found throughout North America and Europe. Season September-November. Not edible.