Who Was Levitan? Poem by Michael Pruchnicki

Anton Chekhov wrote to Maria Kiselyava, commenting -

'deadly as requiring Levitan to draw a tree without any dirty bark or yellowed leaves...'

Who was this Levitan anyway?
A close friend of the writer Anton Chekhov?
An ardent lover of Maria Pavlovna Chekhov?
An artist friend of the painter Mikhail Chekhov?
A writer of rural stories in 19th century Russia?
A classical Russian landscape art painter?
A devotee of a popular genre known as mood landscape?
A character in Chekhov's story 'The Kiss'?
A man who jumps with Robinson from the hotel in Vera Cruz?