Vegetative cells are slender, flexible rods with tapering ends, often
long, needle shaped. The fruiting bodies are either naked
masses of slime and myxospores, of cartilaginous consistency,
and of very variable size and irregular shape, or, in most cases,
are made up of pale to deep brown sporangioles in various arrangements,
with or without a slime stalk or pedicle. Myxospores
are short, optically refractile rods to spheroids, but in the latter
case always slightly deformed and accompanied by short rods,
with rounded or tapering ends.