Cladonia portentosa is a species of lichen that belongs to the family Cladoniaceae. It is also known as the British Soldiers lichen due to its resemblance to a line of soldiers. This lichen is a fruticose lichen, which means it is a lichen that grows upright or hangs down like a beard. It has a bright red apothecium or fruiting body that sits atop a slender stalk which can grow up to 10 cm (4 inches) tall.