The term "Prunus × hillieri" does not correspond to a widely recognized or formally documented plant taxon in major botanical databases, including those maintained by the Royal Horticultural Society, Plants of the World Online (Kew Science), or The International Plant Names Index (IPNI).
Accurate information is not confirmed regarding the classification, origin, or description of a plant named Prunus × hillieri. It may be an unpublished, invalid, or incorrectly cited name. The "×" in the binomial suggests it is intended to represent a hybrid within the genus Prunus, which includes cherries, plums, almonds, and peaches. Hybrid designations in this genus are common, especially in horticultural contexts (e.g., Prunus × yedoensis).
The name "hillieri" could potentially honor someone with the surname Hillier, possibly referring to the Hillier family known for their work in horticulture and the Hillier Nurseries in the United Kingdom. However, no verified record confirms a Prunus hybrid by this name.
Given the absence of reliable sources, Prunus × hillieri is not currently recognized as a valid botanical name. It may be a misapplication, an informal cultivar designation, or an erroneous reference. Further taxonomic clarification or primary source documentation would be required to confirm its status.