adh_mo-172393_1 adh_mo-172393_2 adh_mo-172393_3b

Perenniporia fraxinea (Bull. : Fr.) Ryvarden

Nova Hedwigia 27: 158 (1976)

Fruitbody:
Fruits from base of live or dead trees or stumps. Spores white, subglobose or drop-shaped, thick-walled, dextrinoid.
Similar species:
The white spores and paler flesh separate it from Ganoderma. Within Perenniporia it is separated by having sessile brackets, pores 4 to 6 per mm, and subglobose spores shorter than 9 micrometers (Gilbertson and Ryvarden 1987). Many of the other species are pored crusts.

Happily, fruitbodies of P. fraxinea have one unique ident. feature which is present at any stage of their development: when cut open, the corky textured flesh is the same creamy fawn colour as the (fresh) exterior. This uniformity of colouration contrasts well with species of the Ganoderma genus and also helps to differentiate P. fraxinea with Rigidoporus ulmarius, another fungus that develops brackets of similar appearance (especially in relation to algal bloom).

J. Forbes-Laird, Monograph on Perenniporia fraxinea.
Ecology:
A "nasty rotter" that should be watched for by city foresters. Perennial pathogen causing white rot in heartwood, at tree base and roots, weakens tree. Typically on Fraxineus (ash) but on many other hardwoods. In British Isles reported from Fagus (beech), Juglans (walnut), Platanus (planetree), Populus (poplar), Robinia (locust), Quercus (oak), Salix (willow), Sambucus (elder), Sophora, Sorbus (rowan), Tilia (linden), and Ulmus (elm).
Phenology:
Recorded for August to November.
Biogeography:
Widespread, at least in Europe and eastern North America.
Chicago Region status:
Rare. Newly documented with five collections from 2014. First time it was found in early August on a club foray in southern Cook County. Rocky worked up the microscopic characters and posted the observation on Mushroom Observer. Five weeks later the second collection was found in northern Cook County by a club member who kindly donated the specimen. Then it was found on three more club forays in northern Cook County from September to early November.
This species, as Fomes fraxineus, was listed in Moffatt (1909) but there were no collections at the Field Museum (F) for this species from anywhere. The six historic collections from 1900 to 1912 were sent to University of California, Berkeley (UC), New York Botanic Garden (NY), and SUNY College of Environmental Science and Forestry Herbarium (SYRF). The UC herbarium labels were printed here, stating: In the Cryptogamic Herbarium, Chicago Natural History Museum. Some of these collections were originally labeled as Fomes fraxineus Bull. (Data from MycoPortal):
  • [UC] W.S. Moffatt 481, 22 Sept. 1900. On standing trunk near ground in woods at Glen Ellyn, Illinois.
  • [UC] E.T. Harper, Oct. 1902. On stumps in River Forest, Illinois.
  • [UC] E.T. Harper & S.A. Harper, Oct. 1903. On Ash stump. River Forest, Illinois.
  • [NY] E.T. Harper, October, sent Nov. 1904. Two seasons on a stump. Riverside, Ill.
  • [SYRF] L. H. Pennington , 06 September 1909, Evanston, Cook County, Illinois.
  • [UC] W.S. Moffatt, Oct. 1912. River Forest, Illinois.
Excerpt:
W.S. Moffatt. The Higher Fungi of the Chicago Region (1909, p. 107).
Fomes fraxineus Bull.
Pileus corky-woody, glabrous, somewhat applanate, whitish, then reddish and brown, at first even, then concentrically sulcate-plicate, pallid within.
Pores minute, short, reddish at first, as well as the margin covered with a white sebaceous down. Odor strong and penetrating.
On stumps. River Forest, Harper; near the ground on a standing trunk, Glen Ellyn. Moffatt. Unfortunately both collectors failed to record the species of tree on which the specimens were found. It is said to grow on Fraxinus americanus.
Type:
in Europe
Taxonomy:
Hopefully DNA analysis has provided a stable home for P. fraxinea. Beyond its initial days in Boletus (1790) and Polyporus (1821), this polypore has been transferred (combined) into Trametes (1882), Fomes (1885), Placodes (1886), Ischnoderma (1889), Scindalma (1898), Ungulina (1925), Vanderbylia (1973), Perenniporia (1976), Haploporus (1983), Poria (1984), and Fomitella (1989). Note this is an example where newer combinations are not the accepted placement. The Perenniporia combination was also published by Ryvarden in 1978 (Polyporaceae of N. Europe 2: 307).
Specimens examined:
P. R. Leacock 11749 [A.D. Houghtby MO-172393], 11992, 12119, 12123, 12222, 12320.
Related links:
Julian Forbes-Laird, Monograph on Perenniporia fraxinea [PDF] from Forbes-Laird Arboricultural Consultancy, UK. ; Wild About Britain ; BBC News: diseased ash tree falls, kills 3 people - (source) ;
Records online:
Mushroom Observer ; MycoPortal
Taxon links:
283597 MycoBank ; Index Fungorum ; Species Fungorum