Green manure, red thinness and metonymy

Rhetoric. Green manure and red thinness are metonymic techniques used by Li Qingzhao in "Like a dream, it rained last night and the wind blew suddenly". In this poem, Li Qingzhao refers to the green leaves of begonia flowers in the green generation, and the red generation refers to the red flowers of begonia flowers, and describes the luxuriant leaves and sparse flowers through adjectives. This metonymy vividly expresses the author's regret over the passing of spring.