Caucasian Peony.  Molly the Witch.

Glaucous foliage on this compact peony.  Lemon yellow single flowers in May.  Molly will grow in sun or partial shade When planting, make sure that the highest bud on the crown is no more than 2" deep in the soil.  A slow release fertiliser can be applied in spring and some well rotted manure will help to keep the rootzone moist and insulated from too much heat or frost.