1、 Morphological characteristics

1. Root: root is divided into main root, lateral root and fibrous root. The taproot is relatively deep and vertically grows underground. It also has lateral roots growing horizontally. Fibrous roots also grow on lateral roots

2. Stem: the stem is upright, with rough surface and bristles. Later, it will be lignified and form hollow inside. The color of embryo stem at seedling stage can distinguish its varieties

3. Leaves: leaves are divided into cotyledons and true leaves. There is only one pair of cotyledons. There are many true leaves, which are opposite or alternate, and there are bristles on the surface

4. Flower: there are two kinds of flowers on the top of the sunflower stem. Tongue shaped flowers grow in a circle around the disk, and tubular flowers grow inside the disk. The color is yellow

5. Fruit: the seeds are long, with black-and-white striped shells outside and edible cotyledons inside, commonly known as melon seeds

2、 Curing method

1. Temperature: sunflower does not require high temperature. It can grow healthily as long as it is higher than 10 ℃

2. Water: sunflower has little demand for water during its growth period. But at the beginning of the bud stage, more water is needed, and less water will reduce the number of seeds

3. Light: sunflower, commonly known as sunflower, is naturally inseparable from light at all stages of growth. Sufficient light can ensure its strong growth, vigorous stems and leaves, and plump seeds

3、 Picture appreciation