Step 1: Understanding the Concept:
Cultivated plums belong to different species with distinct origins, chilling requirements, adaptation profiles, and fruit characters.
Step 2: Detailed Explanation:
'Santa Rosa' is a globally renowned cultivar belonging to the Japanese plum species, botanically classified as Prunus salicina.
It was developed by the eminent horticulturist Luther Burbank in Santa Rosa, California, and released in 1906.
Japanese plums are characterized by earlier blooming, lower chilling requirements, and rounder, firmer, juicier fruits compared to European plums (Prunus domestica).
Santa Rosa serves as an industry standard for fruit quality and is also a major pollinizer variety for other Japanese plum cultivars.
Step 3: Final Answer:
Santa Rosa is classified as a variety of Japanese plum.