Boston fern
Nephrolepis exaltata
Helianthus annuus
Sunflower
A daily rhythm, written in growth.
- Family
- Asteraceae
- Habitat lens
- Open ground
- Growth form
- Herb
- Research lens
- Light response
Explore the specimen.
01A mature head
This photograph records a mature sunflower head. It does not show the growing shoot stage used to investigate daily solar tracking.
02Record the context
To study orientation, record the direction, time, and developmental stage. A close-up without that context cannot demonstrate tracking.
03A question across time
Compare observations of the same plant through the day. The difference between young and mature plants is central to the research linked in this dossier.
A closer look
Small details.
Extraordinary stories.
Young sunflowers can track the sun during the day and reorient overnight. Research links this movement to differences in stem growth and an internal circadian rhythm. Mature flower heads generally stop tracking and face east.
What to look for
Distinguish a growing bud from a mature flower head before making a comparison. Developmental stage matters when describing movement.
Does a young plant respond in the same way as a mature one?
A note on observation
A single photograph cannot demonstrate tracking. Repeated observations, at recorded times, are needed to investigate movement.
Follow the evidence
Habitat labels are broad browsing categories, not complete distribution records. This dossier is an editorial introduction, not original field research.
Photograph & license
George Chernilevsky. Original photograph · CC BY 4.0. Resized and converted to WebP; displayed crops may vary.
