Image of Blueing Bracket

Description:

Update information: This observation was first determined as Postia caesia (see former text in brackets below). But, a kind explanation of Mr. Gnter Sturm, Germany, having long 'mileage' in Polyporaceae, and the paper of David (1974), Ref.: (8) convinced me that the correct determination should be Postia subcaesia. Now substratum fits better. Also habitus of the find fits better to the new determination. Pileus of P. caesia is of more uniform colors and never as strongly zonate as in this observation. Another trait, which fits better now, is the fact that the pilei color didn't changed distinctly blue when bruised. Nevertheless, spore dimensions still don't fit to data from literature. May be Ryvarden's comment in Ref.: (7), p 405, regarding distinguishing both species: 'However, there are some disturbing intermediate specimens on hardwoods.' explains the situation? ----------------------- ((Slo.: modri skutovec - Habitat: Mixed forest, Picea abies and Fagus sylvatica dominant, almost flat terrain, calcareous ground; full shade; humid place, partly protected from direct rain by tree canopies; average precipitations ~ 3.000 mm/year, average temperature 4-6 deg C, elevation 1.000 m (3.300 feet), alpine phytogeographical region. - Substratum: on dead rotting branch laying on ground and on half buried rotten roots of Fagus sylvatica, partly still in bark. - Comments: This beautifully blue polypore may also be Postia subcaesia, syn.: Oligoporus subcaesius. Unfortunately, the distinguishing traits between P. caesia and P. subcaesia seem to be treated quite inconsistently in the literature. Postia caesia should principally thrive on wood of conifers (with rare but well documented exceptions) and should have spores wider than 1.5 , while Postia subcaesia is found on broadleaved trees and should have spores narrower than 1.5 (as per Refs.:(5), (6) and (1)). Contrary, Ref.: (4) states narrower than 1.5 spores for P.. caesi (mistake?). Also the information about spore shape (allantoid versus cylindrical) and pilei size is inconsistently given in different sources. In this observation measured spore width speaks in favor to P. caesia (according to Ref.:(1), (6) and (5)), while substratum doesn't. Since exceptions with regard to substratum of P. caesia are known, and based on quite distinctively blue color of the pilei I decided for P. caesia, but this may be wrong. - Growing in a small group of about 6 pilei of different size; pileus up to 6 x 4 cm across; flesh soft, fibrous; SP very faint, whitish(?), oac857(?). - Spores smooth, cylindrical and moderately allantoid. Dimensions: 5.3 (SD = 0.2) x 1.6 (SD = 0.1) , Q = 3.25 (SD = 0.26), n = 30. Olympus CH20, NEA 100x/1.25, magnification 1.000 x, oil, in water.AmScope MA500 digital camera. - Herbarium: Mycotheca and lichen herbarium (LJU-Li) of Slovenian Forestry Institute, Vena pot 2, Ljubljana, Index Herbariorum LJF - Ref.: (1) Personal communication with Mr. Mr. Guenter Sturm. Id'ed by Mr. Guenter Sturm. (2 ) J. Breitenbach, F. Kraenzlin, Eds., Fungi of Switzerland, Vol.2. Verlag Mykologia(1986), p274. (3) A. Bernicchia, Polyporaceaes.l., Fungi Europaei Vol.10., Edizioni Candusso (2005), p 359. (4) S. Buczacki, Collins Fungi Guide, Collins (2012), p 490. (5) R. Phillips, Mushrooms, Macmillan (2006), p 313. (6) G.J. Krieglsteiner (Hrsg.), Die Grosspilze Baden-Wrttembergs, Band 1, Ulmer (2000), p 560. (7) L. Ryvarden, R.L. Gilbertson, European Polypores, part 2., Synopsis Fungorum 7., Fungiflora A/S (1994), p 435. (8) A. David, Une nouvelle espece de Polyporaceae: Tyromyces subcaesius, Bull. Soc.Linn. Lyon, Vol.46. (1974), pp 119-126.))