Sunflower. Macrophotograph of the flowering head of a sunflower (Helianthus sp.). This flower is actually a composite of many small true flowers. Dark disc florets are clustered in the centre,with petal-like ray florets (yellow) around the edge of the flowering head. This arrangement is characteristic of the family Compositae,to which the sunflower belongs. This is the largest family of flowering plants. Sunflowers are known for their ability to track the Sun. They do this as the growth hormone auxin accumulates in the shaded parts of the stem,causing those parts to grow more quickly. Sunflowers are a popular garden plant,and may reach over three metres in height | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Rauch, Bonnie Sue |
Taille de l’image : | 3606 px × 5534 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : |
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