Helianthus
Yes they are endangered
You need to be growing the proper species. Not all of them will grow that tall. Look for "Giant" sunflower seeds.
it depends on the type of sunflower
With the exception of Jerusalem artichokes, all domesticated sunflower varieties are annuals. There are a few wild species that are perennial.
There are about 70 species of sunflower, the more common domestic varieties flower in late spring, summer and into early autumn
It cannot live on Mercury because the atmosphere is too tenuous.
Up to 1,000 seeds can be produced from one sunflower head. Some may produce more or less depending on the exact sunflower.
Each sunflower head can contain as many as 800 to 2000 seeds. These seeds can vary in appearance, but the most common type used for snacking is black with a white stripe pattern on the hull. These seeds are the means of sunflower reproduction, and can be planted to grow into a new sunflower the following growing season.
Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds.
sunflower oil, bird seeds
one cup of sunflower seeds (with shell) is 7.5 in point plus