Peziza succosa is a cup fungus that is easily identified by the yellow milk that exudes from the ascocarp when cut. It grows on the surface of disturbed soil and was believed to be saprobic (Hansen and Pfister, 2006 Mycologia 98 pp. 1029-1040). However Tedersoo et al. (2006, New Phytologist 170 pp. 581-596) isolated P. succosa from ectomycorrhizal root tips from forests in Estonia and Denmark, suggesting it is an ectomycorrhizal symbiont. It grows to 2-5 cm in diameter and has no stem. Microscopically, its ascospores are 17-19 x 9-10 μm in size and have 2 guttules or storage lipids and 2 μm warts on the spores (Spooner, 2001 Field Mycology 2 pp. 51-59).