Crepidotus cesatii

Description

Crepidotus cesatii is a member of the Crepidotaceae family from the order Agaricales. It is kidney-shaped or shell-shaped, surface smooth to finely downy, lobed, margin often notched, whitish to pale brown, to about 20mm across, but often less. Gills fairly distant, whitish then pinkish brown. Grows on twigs and branches, usually from deciduous trees.

Agaricus cesatii Rabenh is a synonym.

Common names: Roundspored Oysterling.

Mushroom Identification

1. Cap

   0.5 to 2cm in diameter, shell-shaped to kidney-shaped and often with a slightly scalloped margin, the cap is initially white, turning creamy-ochre with age; laterally attached to its substrate - usually small twigs or branches among leaf litter - via its cap, rather than with a stipe. Infertile surface smooth to finely downy.

2. Gills

   The gills, which radiate from the point of attachment, are widely spaced; some gills forking. White at first, they gradually turn pinkish brown or dingy yellowish pink. Basidia 4-spored.

3. Stem

   Almost invariably this little woodland mushroom has no stipe (stem) at all.

4. Spores

   Subglobose, ornamented with minute spiny warts, 6.5-8.5 x 5-7µm.

5. Spore Print

   Pinkish buff.

6. Odor and Taste

   Not distinctive.

7. Habitat

   Saprobic, on rotting fallen twigs and branches in deciduous and sometimes coniferous woodlands and at the bases of hedgerows.

8. Season

   August to December.

9. Similar Species

   Crepidotus variabilis is macroscopically similar but has elongated oval spores.

History

The Roundspored Oysterling was described by German mycologist Gottlob Ludwig Rabenhorst (1806 - 1881), who established its basionym when he gave it the binomial scientific name Agaricus cesatii. It was Italian mycologist Pier Andrea Saccardo who transferred this species to the genus Crepidotus, whereupon it acquired its currently accepted scientific name Crepidotus cesatii.

The generic name Crepidotus comes from crepid- meaning a base, such as a shoe or a slipper. Although some sources state that it means 'cracked', and -otus, meaning an ear - hence it suggests a 'slipper-like ear'. In the past mushrooms in this genus were sometimes referred to as slipper mushrooms. The specific epithet cesatii honors the Italian botanist Vincenzo de Cesati (1806 – 1883).

Photo sources:

Photo 1 - Author: vhamon (CC BY-NC 4.0)

Photo 2 - Author: lenaquist (CC BY-NC 4.0)

Photo 3 - Author: fungiwoman (CC BY-NC 4.0)