Blushing Rosette

Blushing Rosette is a widespread, highly variable, ground-dwelling polypore. It occurs in Europe, Asia, Australia, southern Africa, and the Americas. In the United States, it occurs east of the Great Plains and west of the Rocky Mountains, with a few scattered records between.

Blushing Rosette appears in summer and fall, alone or in groups but not clustered (gregarious). It grows on the ground around the base of both stumps and living deciduous trees, and occasionally around conifers. It gets its nutrients from dead and decaying wood. When found near a dead stump, it causes white rot in the dead wood. When found near a living tree, it is assumed to be growing on the roots, and it causes white trunk rot in the living wood.

Blushing Rosette has two very different forms. This, and its worldwide distribution, has caused it to be described many times under many scientific names, with the result that today there are more than fifty synonyms for this species.

The “normal” form takes the shape of a typical polypore, usually with a single cap, sometimes with multiple caps fused together into an overlapping rosette. The cap may be light brown, tan, reddish brown, or wine red. It is sometimes faintly concentrically zoned, and the margins are usually pale. It is usually 1¼″ to 3¼″ (3 to 9 cm) wide, but when growing alone it can be up to 8″ (20 cm) wide. It can be round, semicircular, or kidney shaped, or it can have an irregular shape, but it is always convex above and flat below (planoconvex). The upper surface is dry. It is usually densely or moderately covered with short, dense, matted, woolly hairs, but it is sometimes almost hairless.

The pore surface is whitish to buff at first, but it becomes dingy with age, and it bruises pinkish to reddish brown or reddish to pinkish brown. When fresh, it sometimes exudes reddish droplets. The pores are 1⁄32″ to ⅛″ (1 to 3 mm) wide and up to 3 ⁄16″ (5 mm) deep. They appear stuffed at first, becoming angular, irregular, or maze-like as they age, and sometimes tooth-like on older specimens.

The stalk may be well developed or poorly developed, or there may be no stalk. When present, the stalk is 1¼″ to 4″ (3 to 10 mm) long, and ⅜″ to 1¼″ (1 to 3 mm) thick. It may be laterally or centrally attached to the cap. It is hairy, colored like the cap, and often encrusted with dirt.

The flesh is white, pinkish, or pale tan. The edibility is unknown, but it is too tough to eat.

The spore print is white.

The “aborted” form is an irregular mass of pore surface. It may have a single cup-like shape, or it may be cauliflower-like, with numerous separated, rounded projections.

Deciduous and occasionally coniferous trees and stumps

Summer and fall

Sources

4, 7, 24, 26, 29, 30, 77.

Widely distributed but not common

Family
There is some disagreement about the correct placement of the genus Abortiporus. MycoBank, MycoPortal, BOLD, BioLib, IRMNG, and NatureServe place Abortiporus in the family Meruliaceae. IndexFungorum, GBIF, NCBI, Catalogue of life, MushroomExpert.com, Mushroom Observer, and iNaturalist place it in the family Podoscyphaceae.

uploaded to iNaturalist.org

Abortiporus biennis Greece by Theo
Θεόδωρος Φωτιάδης

Abortiporus biennis. Champimaginatis. English Text
jean pierre Piétri

Periode 8 Abortiporus Biennis
Squishysubmarine

Matthew Knott
6/17/2024

Location: Spafford Park, Cloquet, Minnesota
Lat/Lon: 46.72648, -92.46629

uploaded to iNaturalist.org