The giant grey and mammoth Russian are two commonly grown sunflowers known for large heads and seed production. The mammoth Russian is known by a number of names, most of which include the word "Russian" or the word "mammoth." These two varieties can grow to 10 feet tall and form heads up to 1 foot in diameter. The seeds are used as wildlife feed, sometimes left in the head, or as human snack food, roasted and salted in the shell.
The Lyng’s California greystripe grows to about 7 feet tall with brown heads about 10 inches in diameter. This flower is ornamental and known for its long rays. Rays are specialized colorful leaves that look like flower petals and form around the head, which comprises hundreds of tiny flowers that produce the seeds. The Lyng's California greystripe is known for its uniform height, which produces an attractive ornamental presentation.
The head of the sunbeam sunflower is smaller than that of other varieties, and the plant is much shorter and grows well in smaller ornamental gardens. This plant reaches a height of about 3 feet and produces heads of about 6 inches in diameter; this is a larger head than those of other dwarf or smaller sunflower varieties. This plant produces numerous short, bright-yellow rays around the flower head.
The Maximillian sunflower grows wild in some parts of the United States. This plant is a perennial, meaning it grows from the roots each spring, and is hardy to the northern tier of the United States. It grows to heights of about 8 feet and produces flower heads of about 3 inches in diameter.