Epithet = from Ohio. Genus = truncate - spore (it more commonly means tree trunk - spore; the name should have been Truncatospora).
Perennial, very small, tough, hoof-shaped bracket. May have narrow cap edge when it is more resupinate. Upper surface ridged (sulcate), sometimes zonate; pale then brown, older parts black. Small white pores are round, thick-walled, 5–6 per mm. Context is white to pale brown. Spores hyaline, elliptical, thick-walled, truncate at end with germ pore (9.5–13 × 6.5–9.5 µm).
This is our smallest perennial bracket. Most other small polypores are not this firm in texture, or perennial with this shape. But Datroniella scutellata (Datronia) is very similar. The two species are confused easily and old herbarium collections should be checked. D. scutellata makes an annual bracket, upper surface is soon dark brown to black, pores white to brown, context pale brown; spores large and cylindrical; grows on various hardwoods, often on alder in northern Great Lakes Region. Truncospora wisconsinensis has white annual brackets, larger pores (3–5 per mm), dimitic hyphal system, and smaller spores (9–11 × 6–7.5 µm).
See genus page for more species.
Saprobe on dead hardwoods, causing white rot. Typically on logs that have lost their bark (decorticated). Elsewhere reported from fence posts and fence rails. So it is apparently adapted for drier or exposed wood.
Perennial brackets can be found year-round.
Widespread across eastern North America. This is an American species not seen in Europe.
Spirin et al. (2015) did not list any western specimens. The Gilbertson 16372 specimen on oak in Arizona is the segregate species Truncospora arizonica.
Chicago Region status
Fairly common. Found in oak woodland, in mixed hardwoods, and oak savanna. We have 300 observations over 20 years but 85% of these records are from plot studies because it is easily overlooked.
Two historic records are from River Forest and Riverside on west side of Chicago.
More than 100 collections from Chicago Region. I usually find only a few at a time. The fruiting represented by PRL 11806 was exceptional with more than 50 fruit-bodies. Photos are from McHenry County, P.R. Leacock 11521, and Cook County, P.R. Leacock 11806.
Taxon Details and Links
Acta Musei Nationalis Pragae 9B (2): 108 (1953)
This little species was also transferred to Ungulina (1900), Ganoderma (1927), Fomitopsis (1941), and Poria (1959). Spirin et al. (2015) described six new species in the Truncospora ohiensis group; some are found in Arizona, Texas, Florida and Mexico.
Spirin V., J. Kout, J. Vlasák. 2015 (2014). Studies in the Truncospora ohiensis – T. ochroleuca group (Polyporales, Basidiomycota).
Nova Hedwigia 100: 159-175. DOI: 10.1127/nova_hedwigia/2014/0221
Zhao, C-L., F. Xu, D. H. Pfister. 2016.
Morphological and molecular identification of a new species of Truncospora (Polyporales, Basidiomycota) in North America.
Phytotaxa 257 (1): 89–97. DOI: 10.11646/phytotaxa.257.1.7