2. Flowers bloom in autumn. Purple, arranged in axillary, dense and lateral racemes; Bracts broadly ovate or suborbicular, ca. 4 mm long, with reddish-brown glandular spots, glabrous;

3. The cotyledons of Perilla frutescens are by-products. Leaf picking should begin in August, and it should be done after dewdrops fall on sunny days to prevent heat deterioration. The leaves should be fresh and complete, and the leaf surface should be 5 cm ~ 7 cm long, and should be picked together with the petiole.