prl12291_a prl12291_b

Ceriporia spissa (Schwein. ex Fr.) Rajchenb.

Mycotaxon 17: 276 (1983)

orange poria. Scientific name = dense horn-pore.
Annual effused poroid crust, spreading over wide area; up to 3 mm thick. Brightly colored orange, reddish orange to brownish orange, drying reddish brown. Margin pale and matted mycelioid. Texture cheesy or rubbery, can peel or scrape off the log. Pores very small at 7 - 8 per mm. Spores are narrowly allantoid (sausage-shaped).
Similar species:
Similar pored crusts have different coloration, larger pores, or different spores.
White rot on dead hardwoods, less common on conifers.
Summer and fall; July to November for Chicago area.
North America, Cuba, in French and British Guiana, Ecuador, Canary Islands (Spain), Tahiti, New Zealand, and reported from Japan. Note that old historic collections must be physically verified; two-thirds of the Field Museum collections labeled as such are obviously not this genus.
Chicago Region status:
Rare. Five collections known for Chicago.
The nearest historic collections are from Geneseo in western Illinois, collected by E. T. Harper, August 1915, and then split between several herbaria (BPI, MICH, TENN, UC); but these are likely misidentified. The species Poria spissa is incorrectly described in Moffatt (1909, p. 122, as perennial!), giving three Chicago area locations, but the herbarium specimens are a perennial, resupinate Phellinus.
Specimens examined:
The Morton Arboretum herbarium has a collection from their east woods made by Arboretum naturalist Richard Wason in November 1988. We found it recently on a foray in northern Cook County, October 2014. I looked through our unknowns and found one more collection, August 2000, for southern Cook County. Then it was found again in July 2015 in northern Cook County.
USA, North Carolina, Juglans trunk (walnut).
Apparently the name by Fries is based on the earlier Schweinitz name since the type specimen was from a Juglans trunk. This species was also transferred to Mucronoporus (1889), Physisporinus (1942), Meruliopsis (1968), Caloporus (1973), Ceriporia (1985), and Gloeoporus (2006). See links below for other synonyms. See the Rajchenberg link below for a discussion of its resemblance to Meruliopsis taxicola (Caloporus), a merulioid species that has a continuous hymenium over the folds.
Description links:
Rajchenberg, M. 1983. Cultural studies of resupinate polypores. Mycotaxon 17: 276 (1983). Libri Fungorum page image
Related links:
Wisconsin Mushrooms ; Les champignons du Qu├ębec ; Photos, University of California, Berkeley. ; Mykoweb California.
Records online:
Mushroom Observer ; MycoPortal
Taxon links:
108755 MycoBank ; Index Fungorum ; Species Fungorum