The Collaborative International Dictionary of English v.0.48:

Henware \Hen"ware`\, n. (Bot.)
   A coarse, blackish seaweed. See Badderlocks.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Badderlocks \Bad"der*locks\, n. [Perh. for Balderlocks, fr.
   Balder the Scandinavian deity.] (Bot.)
   A large black seaweed (Alaria esculenta) sometimes eaten in
   Europe; -- also called murlins, honeyware, and henware.
   [1913 Webster]