Fig. 1. The sunflower shoot apex tracks the sun during the day and reorients at night,
facing east well before sunrise. (A) Stills from a time-lapse photography series taken
every 30 minutes using a consumer camera and a dim-solar powered light to enable
photography (West = left). Plants were grown in pots in the field in Davis, California,
and images were taken when the plants were ∼2 months old. (B) Daily cycles of the
stem angle relative to the horizontal plane (90◦ = skyward orientation) measured at
first node below apex.
Source: S. Harmer