Nectar in <i>S. officinalis</i> flowers over time.

<p>Sugar concentration (A) and nectar volume (B) of flowers <i>S. officinalis</i> in a growth chamber. Flowers are staminate for days 1–2, and transition to pistillate for days 3–5, and then begin to senesce over days 6–7. Error bars represent standard error of the mean for flowers collected from 10 different plants. An asterisk (*) indicates a comparison that is statistically different from the subsequent day (α = 0.05).