How sunflowers see the sun

> plants grown outdoors, swinging their heads with the sun, showed a completely different pattern of gene expression. ... The researchers have not yet identified the genes involved in heliotropism.

short version: "we dunno yet, but it isn't what we thought it might be." real science i love it.

makes me wonder how much of the flower face one could obscure with solar cells before it stops tracking. "bio-assisted tracking system to maximize full day output" sounds suitably sexy as a sales pitch.

maintenance would be difficult but thats an implementation detail. Surely that can be worked out with AI robotics and another few hundred million in runway funding.

see also Niven's "Slaver Sunflowers"

Maybe this is a dumb question but why does a sunflower’s seed face need to face the sun daily? Isn’t it the leaves that need to photosynthesize?

Do sunflowers still track the sun’s location on cloudy days?