Tuber excavatum Vittad. (illustrated 70% life size) Fruit body about 1.5–5cm across; subglobose, lobed; reddish-olive. Flesh browny ochre; smell slightly nauseating. Spores 22–55×16–40¼, reticulate; 2–4 per asci. Asci 85–125×70–90¼, like a lumpy paper bag. Habitat in broad-leaved woodland; most of the year but mainly autumn. Very rare, possibly because few people search for it. Not edible.