It was a solitary, relatively old specimen on moss-covered clayey soil surrounded only by Ficaria verna. Within a radius of about five meters, not a single Anemone nemorosa could be found.

The mushroom was attached to a superficial buried sclerotium and clung to the roots of a young Ficaria verna plant.
Microscopy confirmed Dumontinia.

However, the fact that it occurred with only Ficaria deprives me of any certainty.

Is the occurrence of Dumontinia with only Ficaria a known phenomenon?

Macroscopic:
° apothecium: saucer-shaped; 16.5 mm diameter
° stalk: 7.5 mm and 1.7 mm diameter; black
° sclerotium: 11x8.5 mm; black, wrinkled; contents cottony against the wall somewhat gelatinous and yellowish

Microscopic:

° asci: IKI+; with croziers
° layer of elongated cells present against ectal excipulum
° spores: with 4 nuclei; elongated ovoid; one apex often slightly blunter than the opposite; mature not pinching off conidia;
- measurement 1 (free spores in preparation in water): (13.4) 14.1 - 16.6 (16.8) × (6.7) 6.8 - 7.4 (7.7) µm
Q = (1.9) 1.93 - 2.4 (2.5) ; N = 17
Me = 15 × 7.1 µm ; Qe = 2.1;
- measurement 2 (in spore in water): (12.9) 14.1 - 16.6 (17.2) × (6.1) 6.3 - 7.5 (8.6) µm
Q = (1.8) 1.9 - 2.5 (2.8) ; N = 35
Me = 15.2 × 7 µm ; Qe = 2.2

Thanks in advance,
William

Hans-Otto Baral, 30-03-2026 14:41

Re : Dumontinia on Ficaria?

First, your fungus is clearly D. tuberosa but I prefer to call it Sclerotinia tuberosa. The differences in the excipulum to S. binuceata are not sharp.

I experienced the same: I saw only Ficaria at a radius of about 1 m, but I strongly presume that the sclerotium was formed from Anemone roots the year before, and the plant disappeared since then. Sclerotinia spp. are parasites, who knows if they are able to kill their host.

I think conidia would be formed in your specimen when kept in a moist box for 1-2 weeks.

About the location I am unsure: Is it NW of Blauwhuis in West Vlaanderen?