Summary: Features include 1) a spherical, brown fruitbody that is floccose or powdery at first, 2) a smooth, shiny, brown interior, 3) numerous, small, irregular, grayish brown eggs that have a cortex of much branched, thick-walled, densely fused, inseparable hyphae, and 4) growth on wood including driftwood.
Microscopic: spores 6-10 x 4-7 microns, colorless; cortex of egg of much branched, thick-walled, densely fused, inseparable hyphae, (Brodie)
Notes: Nidularia pulvinata is found at least in BC where it is fairly common on driftwood, ON, and SC; it is widely distributed but rarely abundant in North America, (Brodie).
Habitat and Range
SIMILAR SPECIES
Nidularia deformis is very similar except for the eggs which are lenticular, reddish brown, wrinkled when dry and have a cortex composed of thick-walled, separable hyphae that are sparsely branched, but "It may be precarious to separate the two above entities on the basis of the colour of the peridioles; in the material that has been seen, both European and American, there is considerable variation in the shade of brown displayed by the peridioles. The nature of the hyphae of the cortex may prove to be a more reliable criterion for separation", (Brodie, discussing Nidularia farcta). A third undescribed species may occur in North America that is "macroscopically similar to N. farcta but differs in the cortical hyphae of the peridioles being much branched, which is intermediate between those of N. farcta with simple very sparsely branched hyphae and N. pulvinata with much-branched densely interwoven hyphae", (Palmer in Brodie).
Habitat
on a variety of kinds of old wood, occasionally on driftwood; moist mixed hardwoods in Ontario, fairly common on driftwood in BC, (Brodie)