Sunflowers from the Terra metaroom are a simple plant which brighten up the landscape and provide habitat for caterpillars. They have a relatively long lifecycle, and do not produce any edibles for creatures.
Sunflowers from the C12DS metaroom are a potted plant that produces edible seeds that are high in starch. The pot is hidden until the sunflower is picked up by the Hand.
More: Freya made two sunflower COBs with edible seeds for C1.