花的颜色是由花瓣细胞中的酸碱度所决定的。花瓣细胞中含有葡萄糖变成的花色素,当它是酸性时呈红色,而且酸性越强,红得越深;当它是中性时则呈现紫色;当它是碱性时,就呈现蓝色,而且碱性越强,蓝色也就越深。像墨菊、黑牡丹等少数花卉,它们的花瓣细胞液是强碱性的,故其花为黑色,成 The color of the flower is determined by the pH in the petal cells. Petal cells contain anthocyanins that glucose turns into, red when it is acidic, and the more acidic, the darker the red; the purple when it is neutral; the blue when it is alkaline , And the more alkaline, the deeper the blue. Like mellow chrysanthemum, black peony and a few other flowers, their petal cell liquid is strong alkaline, so its flower is black, into