Perenniporia fraxinophila

Perenniporia fraxinophila (Peck) Ryvarden

[Fomes fraxinophilus]

ash heart rot.
Epithet = loving ash (Fraxineus). Genus = perennial pored.
Perennial, single or overlapping conks formed on trunk and main branches. Upper side narrow to wide, with a rounded whitish margin, older parts gray to black and cracked. Pores whitish, 3–5 per mm. Flesh pale brown to moderate brown. Spores are white, 9–11 μm, elliptical, thick-walled, truncate at end with germ pore.
Similar species
Truncospora ohiensis (Perenniporia) is small and has larger spores. Other bracket-shaped Perenniporia are differently colored. Ganoderma has smaller pores and the pore surface bruises brown; has brown spores. Phellinus has brown pore surface and darker brown context, turns blackish with KOH; has brown spores. Fomes fomentarius is more hoof-shaped and has brown pore surface; typically on birch or beech. Fomitopsis pinicola, typically on conifers, has an orange or reddish zone on top; causes a brown rot.
Pathogen of ash, some reports on other hardwoods, also juniper (in Arizona). White mottled rot, mainly heartwood(?)
Perennial brackets can be found year round.
Known only from North America (Gilbertson and Ryvarden 1987). Widespread across the range of ash in the U.S.A. and adjacent Canada; rare on the West Coast, absent from Gulf Coast.
Chicago Region status
Rare, even though ash trees are common. Only recently collected from 2011, 2012, 2013, 2015, on ash trees on north-west side of Chicago. Also found in 2015 on live ash in Kane County and dead ash in DuPage County. Historic collections: E.T. Harper, River Forest 1897 [UC]; V.O. Graham, Glenview 1940 [BPI, NY, UC]; C. B. Stifler, Evanston (approx. 1930's) [BPI]; and J.C. Carter, Hinsdale, DuPage County 1944 [ILLS]. Reported for River Forest and Glen Ellyn in Moffatt (1909).
Specimens examined
P.R. Leacock 8626, 10335, 10842, 12367, 12505; C. L. McAllister 110.

Taxon Details and Links

  • Perenniporia fraxinophila (Peck) Ryvarden, Norwegian Journal of Botany 19: 143 (1972)
  • ≡ Basionym: Polyporus fraxinophilus Peck, Botanical Gazette Crawfordsville 7 (4): 43-44 (1882)
  • Fomes fraxinophilus (Peck) Sacc., Sylloge Fungorum 6: 172 (1888)
U.S.A. Dakota or Arizona?
Type Description
C.H. Peck, New Species of Fungi. Botanical Gazette Crawfordsville 7 (4): 43-44 (1882)
Polyporus fraxinophilus.— Pileus sessile, thick, corky, more or less ungulate to somewhat decurrent, concentrically sulcate, rimose when old, the first year whitish, then gray or cinereous, finally black, the margin obtuse, the substance obscurely zoned within, at first whitish, then isabelline; pores medium size, stratose, nearly plane, subrotund, the dissepiments obtuse, entire, whitish; spores white, broadly elliptical, .0003-00035 of an inch long, .00025-0003 broad.
Pileus 2-4 inches long, 1-2 inches broad.
Dead or languishing trunks of ash trees. Dakota. C. W. Irish. Arizona. C. G. Pringle.
This Polyporus belongs to the Fomentarii. It varies considerably in shape, some specimens being almost as much flattened as the thicker forms of P. applanatus, others being as thick as the ordinary forms of P. fomentarius. Specimens three or more years old are somewhat tri-colored, the oldest part being black and full of chinks or cracks, the margin whitish and the intermediate part gray or cinereous. The annual additions are separated by concentric grooves. In the Dakota specimen the annual additions are much broader than in the Arizona specimens, and the pileus is more flattened and thinner. The interior substance is at first whitish but it changes with age to a brownish-yellow or isabelline hue, thus forming a connecting link between the second and third sections of this tribe as given in the Epicrisis of Fries.
This species has also been transferred to Scindalma (1898) and Poria (1964).
Michael Kuo.
Gary Emberger.
USFS Forestry Images
Mushroom Observer
Index Fungorum and Species Fungorum

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Cite this page as: Leacock, P.R. (2018 May 07). Perenniporia fraxinophila - MycoGuide. Retrieved from

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