Lactuca sativa
 
This rare Syrian summer lettuce is the green version of the better-known heirloom Spotted Aleppo.  Both varieties are medieval in origin and may even date to the Byzantine era. The original seed traces to the open market in Homs, Syria where it was discovered in 1949.  A white-seeded Cos/Romaine type, it grows 12-14 inches tall and should be planted 12 inches apart. Very crispy and sweet.
 
~50-60 seeds per packet.