*blue-bottle*

, n. 1. (Bot.) an annual Eurasian plant (Centaurea cyanus) which grows in grain fields; -- called also bachelor's button. It receives its name from its blue bottle-shaped flowers. Varieties cultivated in North America have showy heads of blue or purple or pink or white flowers
Syn. -- cornflower, bachelor's button. [ 1913 Webster + WordNet 1.5 ]

2. (Zool.) A large and troublesome species of blowfly (Musca vomitoria). Its body is steel blue. [ 1913 Webster ]