This plant resulted from xJohnsoni backcrossed to Vittata. It resembles the Amaryllis vittata-rubra (below right) from an anonymous German collection of 1854.
Old House Gardens carries a version of Amaryllis x johnsoni very similar to this Amaryllis rubra-vittata in their Rare and Unusual section.
Amaryllis regina-vittata of Trans. Roy. Hort. Soc. (1820) is yet another
variation on the "Johnsonian" theme.