Rhodonia placenta

Description

Rhodonia placenta is a rare polypore that can be found on rotting stumps and fallen branches of coniferous trees, where separate fruitbodies expand and often fuse into large irregular patches. The pink or orange fertile surface is particularly distinctive, although the physical form of fruitbodies, and in particular the shapes of the pores, are very variable.

This type of decay differs sharply from white rot fungi such as Phanerochaete chrysosporiu m which simultaneously degrade lignin and cellulose. Both white and brown rot fungi are common inhabitants of forest litter where they play an important role in carbon cycling.

Common names: Pink Pancake Crust.

Mushroom Identification

1. Fruit Bodies

   Annual, spread out, thick, attached to the substrate, irregular in shape, merge into formations up to 40 cm long, 8-12 cm wide, soft, watery, juicy when fresh, hard when dried. The edge is narrow, up to 1 mm wide, sterile, wavy, fringed, and clearly defined, with age it often separates from the substrate or disappears altogether. The litter is very thin, whitish, or pinkish, at a young age gelatinous, waxy, dense, hard, and brittle when dry. The smell is weak, sour-sweet.

2. Hymenophore

   The hymenophore is tubular. The surface of the hymenophore is whitish with a pinkish-orange tint, bright salmon-pink, and creamy white, when it dries it fades to dirty white, grayish, and brownish. Tubes are single-layered, waxy, 0.5-2 mm long, and often beveled. Pores are rounded or angular-rounded, sometimes elongated, often with torn edges, 3-4 per 1 mm thick.

3. Habitat

   Grows in coniferous and mixed forests, on rotting fallen trunks and stumps of coniferous trees, mainly spruce and pine, rarely. Causes brown destructive wood rot.

Look-Alikes

1. Postia subcaesia and Postia alni

   Both most commonly associated with broadleaf trees rather than conifers have pale bracket-like fruitbodies with a bluish tinge.

2. Postia caesia

   Grows on conifer wood; it has a blue tinge and forms brackets.

3. Postia stiptica

   Usually grows on conifer wood; it is white and forms brackets.

History

Although described scientifically as Boletus incarnatus as long ago as 1801 by Christiaan Hendrik Persoon, this beautiful polypore owes its basionym (first valid specific name) to an 1862 publication by the great Swedish mycologist Elias Magnus Fries. The currently-accepted scientific name Postia placenta dates from a 1986 paper in the journal Mycotaxon by American mycologists Michael J Larsen (1938 - 2000) and F F Lombard (no biographical details yet available).

Postia, the genus name, was established by Elias Magnus Fries in honor of the Swedish naturalist Hampus von Post (1822 - 1911). The specific epithet placenta means flat or slab-like.

Synonyms

• Polyporus placentus Fr., 1861

• Polyporus placenta Fr., 1861

• Physisporus placenta (Fr.) P. Karst., 1882

• Poria placenta (Fr.) Cooke, 1886

• Leptoporus placentus (Fr.) Pat., 1900

• Leptoporus placenta (Fr.) Pat., 1900

• Ceriporiopsis placenta (Fr.) Domanski, 1963

• Tyromyces placenta (Fr.) Ryvarden, 1973

• Oligoporus placentus (Fr.) Gilb. & Ryvarden, 1985

• Oligoporus placenta (Fr.) Gilb. & Ryvarden, 1985

• Postia placenta (Fr.) M.J. Larsen & Lombard, 1986

• Ceriporiopsis placenta (Fr.) Domanski ex Niemelä, 2005

• Bjerkandera roseomaculata P. Karst., 1891

• Physisporus albolilacinus P. Karst., 1892

• Poria monticola Murrill, 1920

• Poria carnicolor D.V. Baxter, 1941

• Poria microspora Overh., 1943

Photo sources:

Photo 1 - Author: Olli Manninen (CC BY-SA 4.0)

Photo 2 - Author: Björn S... (CC BY-SA 2.0)

Photo 3 - Author: Björn S... (CC BY-SA 2.0)