Data from: Pollen limitation, reproductive success and flowering frequency in single-flowered plants

1. Flowering plants exhibit striking interspecific and intraspecific
variation in flower number, which strongly influences the reproductive
success of animal-pollinated plants. However, the reproductive
consequences of producing a single flower are poorly understood. 2. Here,
we test if plants producing a single flower have a reproductive
disadvantage compared to plants producing multiple flowers by combining
field investigation of five deceptive orchids and a survey of published
literature. Pollen limitation was estimated by comparing fruit production
between hand pollination and open pollination. Flowering frequency was
monitored over years to assess the potential advantage of producing a
single flower. 3. Both single- and multiple-flowered species suffered
strong pollen limitation. However, single-flowered species had
significantly lower fruit set and produced fewer seeds per individual,
though they had a significantly higher pollen removal than species with
multiple flowers. A phylogenetically independent contrast (PIC) of 28
species representing four out of the five subfamilies of Orchidaceae
revealed that fruit set was significantly positively associated with
flower number. Both pollen removal and fruit set had a positive
relationship with flower number within the multiple-flowered species. 4.
Synthesis Current data and PIC support the hypothesis that producing a
single flower has reproductive disadvantages. Single-flowered species may
compensate for low female success through high flowering frequency over
years. This study provides insight into costs and benefits of producing a
single flower in deceptive orchids.