Byssonectria terrestris

Description

Byssonectria terrestris is a widespread, circumboreal species. This inedible mushroom has a bright yellow to orange color and small disc-like fruitbodies. It is habitat gregarious to crowded on soil and duff where animals have urinated; montane; spring.

Mushroom Identification

1. Ascocarp (fruitbody)

   These bright yellow to orange fungi start as tiny spheres and develop into bowl-shaped fruitbodies, typically up to 3mm across but exceptionally to 5mm. They have smooth hymenial or spore-producing upper surfaces, while the infertile (outer edge of the cup-shaped fruitbodies) surface is slightly paler and scurfy.

   The short-stemmed cups are initially round but develop irregular margins where they push up against other fruitbodies.

2. Asci

   185-200 x 10-13µm, with eight spores per ascus.

3. Paraphyses

   Paraphyses are structures of sterile tissue between the asci on the hymenial surface.

4. Spores

   Fusiform (spindle-shaped) and smooth with rounded ends, 20-27 x 8-10μm; with two large oil drops and often several smaller drops

5. Spore print

   White.

6. Habitat & Ecological Role

   Saprobic, on well-rotted deer droppings among plant debris, often beside disturbed paths; this species has also been found growing on burnt conifer wood. It is reported to favor high nitrogen levels and a high pH.

History

In 1805 this ascomycete fungus was described by German mycologist Johannes Baptista von Albertini (1769-1831) and German-American Lewis David von Schweinitz (1780-1834); they gave it the scientific name Thelebolus terrestris. The currently accepted scientific name Byssonectria terrestris dates from a 1994 publication in Mycologia by American mycologist Donald H Pfister.

Synonyms of Byssonectria terrestris include Thelebolus terrestris Alb. and Schwein and Sphaerobolus terrestris (Alb. & Schwein.) W.G. Sm.

The specific epithet terrestris means of the earth or the soil, and this ascomycete does indeed grow on soil.

Photo sources:

Photo 1 - Author: Matt Schultz (Public Domain)

Photo 2 - Author: Matt Schultz (Public Domain)

Photo 3 - Author: Matt Schultz (Public Domain)