Group 1 - The arrival of the "Liqiu" solar term marks the beginning of autumn and the end of the hot summer, indicating the start of the harvest season [3][4] - "Liqiu" is the 13th solar term in the 24 solar terms, beginning on August 7, 2025 [1] - The term "Liqiu" signifies the maturity of crops, as explained in ancient texts [2] Group 2 - The phrase "a leaf falling signifies autumn" reflects the sensitivity and poetic nature of ancient observations regarding seasonal changes [5] - The Chinese parasol tree (Wutong) is particularly noted for its early leaf drop, making it a symbol of the approaching autumn [5][6] - Wutong trees are culturally significant, representing auspiciousness and purity, and are associated with various literary references throughout history [6]