Vegetative cells are long, slender rods with tapering ends,
needle-shaped, i.e., with parallel sides and shortly pointed
ends, 0.8 5–15 lm (Fig. BXII.d.68). Sporangioles spherical
or ellipsoidal, bright chestnut brown, glistening, 50–
180 lm in diameter, in groups (sori) of up to 100 in a
common gelatinous, hyaline, colorless slime matrix like a
capsule (Fig. BXII.d.69). Myxospores rather slender rods
with pointed ends, often slightly C- or S-shaped, optically
refractile, 0.8–1.5 2.5–5 lm. Swarm colonies produce a
tough slime sheet with veins (Fig. BXII.d.70), tenacious and
difficult to break, often with extended fields of oscillating
waves, on peptone agar producing a dark red-brown, diffusing
pigment. Grows well on the standard media for myxobacteria.
Relatively simple defined media have been found
for the organism (Reichenbach and Dworkin, 1992)