What are the reasons that the common garden pea, Pisum sativum, was an ideal species to study genetic crosses?

〇 Cross pollination was simple due to the large flower size
〇 Cross pollination could not occur
〇 Pollen and egg cells are produced in separate flowers on the Pisum sativum plant
〇 The plant has distinct varieties
〇 The Pisum sativum plants that Mendel used were true breeding with two distinct genotypes and phenotypes for specific traits