Brassica oleracea major

from The Collaborative International Dictionary of English v.0.48

Savoy \Sa*voy"\, n. [F. chou de Savoie cabbage of Savoy.] (Bot.)
   A variety of the common cabbage ({Brassica oleracea major}),
   having curled leaves, -- much cultivated for winter use.
   [1913 Webster]