A simple observation of single plant flower production

Violeta and Ignasi Bartomeus

As a simple game with the kids, we started counting daily flower production on a single plant of Cistus albidus that we transplanted last year (so it’s 3-4 year old, and 1.5 meters tall). It turned out quite surprising! I was expecting a clear peak of flowering around a normal distribution, but the flowering went on for > 100 days (very rainy season), with two distinctive flowering peaks. When C. crispus started flowering we did the same with another single individual (1 m tall). In this case, the peak is more clear.

Flower production per day of two individuals of two Cistus species. Days start counting from 1 January (day 55 = 23 February). The date of nest completion by three Osmia bicornis species is marked (O.b1, 2 and 3).

We also recorded nest completion by three Osmia bicornis female bees that regularly visited C. albidus. Bee “O.b1” completed two nests, but the other two only one. Note it took a long time for O.b1 to build the second nest!

Conclusions: Now I have way more questions than when I started. I wonder about individual lifetime flower production over years, variability across individuals, relationship with fitness, how this compare to community level phenology patterns, …