Ruta graveolens the isolation of the furanocoumarin chalepensin. The essential oil of "R. graveolens" contains two main constituents, undecan-2-one (46.8%) and nonan-2-one (18.8%). The bitter taste of its leaves led to rue being associated with the (etymologically unrelated) verb "rue" "to regret". Rue is well known for its symbolic meaning of regret and it has sometimes been called "herb-of-grace" in literary works. It is one of the flowers distributed by the mad Ophelia in William Shakespeare's "Hamlet" (IV.5): It was planted by the gardener in "Richard II" to mark the spot where the Queen wept upon hearing news of Richard's capture (III.4.104–105):
Oh Dear! What Can the Matter Be? we do think that we are sadly neglected; Because they don't visit the school. </poem> Oh Dear! What Can the Matter Be? "What Can the Matter Be?", also known as "Johnny's So Long at the Fair" is a traditional nursery rhyme that can be traced back as far as the 1770s in England. There are several variations on its lyrics. The "Oxford Dictionary of Nursery Rhymes" by Iona and Peter Opie traces this song back to an earlier folk ballad, recorded between 1770 and 1780, whose lyrics are: <poem> O what can the matter be And what can the matter