Scientific name: Exidia glandulosa (Bull.) Fr.
Derivation of name: Glandul- means "gland" and -osa
means "an abundance of." Glandulosa refers to the glands
on the surface of the basidiocarp.
Synonyms: Tremella glandulosa Bull.
Common name(s): Black jelly roll.
Occurrence on wood substrate: Saprobic; forming
irregular masses on decaying deciduous wood; May through
Dimensions: Individual fruit bodies are 1-2 cm wide and up
to 1.3 cm high. Extensive masses of fused fruitbodies may be
18 cm or more long.
Description: Brainlike to irregularly contorted gelatinous
fruitbodies, fusing together to form large masses; blackish-
brown to olive-brown or black; surface shiny with numerous
small black-brown glandular dots.
Comments: Figures 4-6 show Trichoderma sulphureum,
an ascomycete parasite of Exidia species.
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Figure 1. The black, convoluted mass of Exidia glandulosa.
Photo © William Roody.
Figure 2. Another view of Exidia glandulosa, just as dark,
just as irregular.
Photo © Dianna Smith.
Figure 3. This is a somewhat dry
specimen. Very dry
specimens may appear as a thin black-dotted crust. With
moisture, dry specimens may rehydrate to a gelatinous
state. Photo © Dianna Smith.
The yellow fungus growing on Exidia glandulosa is
Trichoderma sulphureum (synonym Hypocrea sulphurea),
an ascomycete. Photo © Gary Emberger.
Trichoderma sulphureum parasitizing Exidia
glandulosa. T. sulphureum also seems capable of saprotrophic
growth, occurring on dead wood in the absence of external
evidence of Exidia spp.
Photo © Gary Emberger.
Figure 6. The numerous small dots on the yellow tissue mark
the location of perithecia. Photo © Gary Emberger.