Multiple Headed Sunflower
I harvested twenty seeds from a giant sunflower (12 inches across) last year. I planted them in April and they are about 8 feet tall. Here's the problem- most of the plants are producing multiple heads of smaller sunflowers that emerge from the juncture of the leaf and plant stem. Only three plants are showing apical dominance and producing one large flower, which is what I wanted.
Most sunflowers are hybrids developed for certain characteristics such as large flowerheads, height, color or other features. The offspring of hybrids do not come true from seed. Just check out the diversity in the volunteer sunflowers you find in your garden or near the bird feeder. This lack of consistency makes seed saving frustrating for some or a fun surprise for others. No matter what their looks you can harvest and eat the seeds or leave them for the birds and squirrels to enjoy.