Growing in cosmopolitan wood chips in garden.

Undertook a tooth-sugar stain ~450x

Then upon further reading mounted in iodine at ~1000x.

Tips were blue around operculum. The spores were smooth and without oil inclusions / drops. So indicating P. vesiculosa

Laessoe and Peterson (2019) pg 1321 'most other brown, large peziza species have ornamented spores, or completely different ecology'. The ecology is stated as 'occurs on various forms of compost, middens, fertilized stubble fields, old hay stacks etc. but not on wood, a decomposer.'

This confused me for a while. Since found on wood chip. But realized that wood chip, does not equal a log. And stubble fields and haystacks are similar in being carbon material, on a dirt base.

Thus suggest P. vesiculosa