Genus Stereum Hill ex Pers.

Neues Magazin für die Botanik 1: 110 (1794)

Type: Thelephora hirsuta Willd., Florae Berolinensis Prodromus: 397 (1787)

Below are the five names I have been using in the Chicago Region. There might be some additions with further work. The second list is names that have been used for Chicago Region, such as by Moffatt (1909), and their current status. Some of the synonymy within Stereum is not clear to me.

  1. Stereum complicatum has small bright orange effused discs that fuse together and form reflexed caps, upper surface with short hairs.
  2. Stereum gausapatum has folded effused-reflexed crowded caps on oak, underside stains red when fresh.
  3. Stereum hirsutum has orange underside and effused-reflexed growth; upper surface strongly hirsute.
  4. Stereum ostrea is the large species with zonate caps; base narrowed or not and adjacent caps fused together or not.
  5. Stereum striatum is small with poorly developed upper surface that is shiny and striate; underside pale; typically found on blue beech, Carpinus.
I have been gathering the literature on Stereum hoping to discover the proper names to apply to the kinds we find in the Upper Midwest. There is a loose consensus among American authors on concepts for a set of names but some treatments of the genus are in disagreement, notably the recent book by Ryvarden (2010), which uses St. atrorubrum instead of St. ostrea and includes St. ochraceoflavum but does not mention St. complicatum.
Related links:
Pacific Northwest Key Council: STEREUM in the Pacific Northwest.
Ryvarden, Leif. 2010. Stereoid fungi of America. Synopsis Fungorum 28.
Taxon links:
18596 MycoBank ; Index Fungorum ; Species Fungorum