Answer: Basically seeds have adaptations that ensure they are spread(normally away from the parent plant).
This is a survival mechanism in order to ensure that the specieswont die out if conditions become unfavourable, this also helps toextend the range of the plant.
Seeds evolved various mechanisms in order to achieve this:
Burs to catch on the fur of animals, edible fruit to ensure thefruit and seeds are eaten by animals (and then excreted a distanceaway), wings in order to catch gentle breezes, some are buoyant anddistributed by water and finally some are "explosively" hurled awayfrom the parent plant.
Answer: There are hundreds of different sunflower varieties, but most fall under two categories the oil seed are small and black and are found in bird seed. The confectioners seed are larger, striped, and used for human consumption