Any of several Australian bottle-brushes of the genus Callistemon, especially C. speciosus, which has spiked flowers with conspicuous long red stamens and is often grown as an ornamental shrub in warm countries.
Origin
Late 19th century; earliest use found in Joseph Maiden (1859–1925).
Definition of red bottle-brush in US English:
red bottle-brush
noun
Any of several Australian bottle-brushes of the genus Callistemon, especially C. speciosus, which has spiked flowers with conspicuous long red stamens and is often grown as an ornamental shrub in warm countries.
Origin
Late 19th century; earliest use found in Joseph Maiden (1859–1925).