The cultivated sunflower is an erect, hardy, often unbranched, coarse, stout-stemmed annual herb, with a varying height up to 4 m. The stem is robust, circular in section, 3-6 cm in diameter, curved below the head, and woody when mature. It is filled with white pith that often becomes hollow with age. The root is a taproot, which can penetrate the soil to a depth of about 3 m, with a large lateral spread of surface roots;however, most of the roots generally remain in the first 50 cm.
Related invasive species
- Helianthus annuus
Related Farm Practice
- Soil
The following summary is from Witt and Luke (2017)