blue bonnet

from The Century Dictionary.

• noun A name for the blue titmouse, Parus cœruleus. Also called bluecap.
• noun In botany, same as bluebottle
• noun A name given to the soldiery of Scotland when it was a separate kingdom, from the color of their bonnets; also, any Scotchman: generally as two words. Also bluecap.

from the GNU version of the Collaborative International Dictionary of English.

• noun A broad, flat Scottish cap of blue woolen, or one wearing such cap; a Scotchman.
• noun (Bot.) A plant. Same as Bluebottle.
• noun (Zoöl.) The European blue titmouse (Parus cœruleus); the bluecap.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun low-growing annual herb of southwestern United States (Texas) having silky foliage and blue flowers; a leading cause of livestock poisoning in the southwestern United States
• noun a brimless dark blue Scottish cap with a flat top and a plume on one side