Cultivar 357: Epsilon

Epsilon is a University of Saskatchewan cherry-plum or plum hybrid from prairie breeding work around Sapa x Oka crosses. Sources identify it as a Sapa x Oka seedling with introduction number C59-351 and an earlier reference code (C58-121). The main introduction record gives 1960, while the prairie cultivar index gives 1959. Sources place its introduction in 1959 or 1960. [S1] [S3]

The fruit was described as spherical and about 1 inch across, with bluish black to light purple skin and dark red flesh. Saskatchewan table data says the flesh was juicy, the skin medium tough and astringent, and the flavor sweet, with dessert quality rated fair. The University of Saskatchewan introduction note is slightly more favorable. It calls the flesh firm, the flavor sweetish, and the fruit of good quality. [S2] [S3]

The available sources say little about the plant itself, but they place Epsilon among prairie Sapa x Oka hybrid material developed at Saskatoon. That lineage matters because Sapa and Oka were central to early prairie plum and cherry-plum breeding, where breeders selected darker, higher quality fruit from hardy hybrid backgrounds suited to Saskatchewan conditions. [S1] [S3]

Hardiness is still unclear from the current sources. A Saskatchewan fruit table confirms that Epsilon was grown and evaluated in the province, but it gives no direct hardiness rating. One 1976 bulletin includes an Epsilon in a small fruit context and says that group was tested mainly in Zones 4 and 5, where it showed moderate to severe winter injury. That evidence does not fit cleanly with the plum and cherry-plum records and should be treated cautiously. [S2] [S3]

Summary source basis

• S1: An index of fruit cultivars tested or developed on the Canadian prairies.
• S2: hortfacts_1976_3.pdf
• S3: University of Saskatchewan fruit introductions 1959-1960

This summary currently draws chiefly from hortfacts_1976_3.pdf, with 2 additional supporting sources linked below.

Featured source descriptions

“Skin described as medium tough and astringent; flesh as dark purple and juicy.”
— ^[3]

“Tested primarily in Zones 4 and 5, where it showed moderate to severe winter injury.”
— ^[3]

“Flavor listed as sweet.”
— ^[3]

“Dessert quality listed as fair.”
— ^[3]

Direct parent cultivars

• No direct linked parent cultivars promoted yet.

Parentage claim text

• Listed as 'Sapa' x 'Oka'.
• Parentage listed as Sapa x Oka; mixed open pollinations.

Derived or downstream cultivar links

• No derived or downstream lineage links yet.

Source-story quotations

• C59-351 (C58-121) Epsilon Sapa x Oka Mixed open pollinations 1960 Spherical, skin bluish black, flesh dark red, firm, sweetish, good quality.University of Saskatchewan fruit introductions 1959-1960, p8
• C59-351 (C58-121) Epsilon Sapa x Oka Mixed open pollinations 1960 Spherical, skin bluish black, flesh dark red, firm, sweetish, good quality.University of Saskatchewan fruit introductions 1959-1960, p8
• C59-351 (C58-121) Epsilon Sapa x Oka Mixed open pollinations 1960 Spherical, skin bluish black, flesh dark red, firm, sweetish, good quality.University of Saskatchewan fruit introductions 1959-1960, p8
• C59-351 (C58-121) Epsilon Sapa x Oka Mixed open pollinations 1960 Spherical, skin bluish black, flesh dark red, firm, sweetish, good quality.University of Saskatchewan fruit introductions 1959-1960, p8

Taxonomy context: No family-tree context surfaced yet.

Related cultivars mentioned in source context