Floral Synorganization and Secondary Pollen Presentation in Four Marantaceae from Costa Rica

Abstract

The Marantaceae have one of the most spectacular pollination mechanisms, including proterandry, secondary pollen presentation, and an explosive style movement. Because the flower has only a single chance to become pollinated, floral structures and processes have to be precisely synorganized and synchronized. In this article, Calathea lutea, Calathea platystachya, Pleiostachya pruinosa (all Calathea clade), and Hylaeanthe hoffmannii (Maranta clade) from Costa Rica are investigated. Pollen is transferred from the anther to the style in late‐bud stages. Depending on the arrangement of the respective parts, self‐pollination in the bud is likely in P. pruinosa but is excluded in C. lutea. After pollen deposition, the buds elongate to twice their length, inducing the style’s tension by differential growth. The representatives of the Calathea clade show a high mechanical tensioning of the backward‐bent style (referred to as “additional tension” here). The four species differ in their floral structures in terms o...