Sunflower the Crop
The crop sunflower looks like the annual weed, but is much more robust with a bigger seedhead.
These sunflowers were planted by my old garage in Canada. The gradient of heights (left to right: increasing height) is due to the gradient of light (left to right: increasing light quantity) that the plants received.
Sunflower the Weed
Seedlings emerge. Is the seedling on the far right suffering from herbicide injury? Which herbicide caused it?
Sunflower seedlings injured with acifluorfen, a diphenyl ether herbicide:
Sunflower leaves (left) and seedling (right) injured by bentazon:
Notice the sunflower seedling growing in this bag of hardened cement (below), now that is a hostile habitat. Weedy adaptation is amazing sometimes.
Stems and leaves:
Flowers and seedheads. Notice how the weedy seedheads are much smaller than in the crop. Human selection and adaptation at work.