These varieties are all "Round Seeded" (as opposed to "Wrinkle Seeded").
They are winter hardy, will stand frost and produce a crop early in the season, so can be sown in November to mature from late May. Alternatively sow in March/April for a later harvest. They have a slightly less sweet flavour to the wrinkled seeded varieties, due to a higher starch content.
Sow in a double row 8cm apart, 5-8cm between seeds.