# Flower Position and Clonal Integration Drive Intra-Individual Floral Trait Variation in Water-Hyacinth (Eichhornia crassipes, Pontederiaceae)

## TL;DR

This study shows that flower position and clonal connections in water hyacinth affect how flowers develop, helping the plant maintain reproductive traits even when resources are scarce.

## Contribution

The study reveals that clonal integration buffers floral traits against resource limitations in water hyacinth, contributing to its invasive success.

## Key findings

- Basal flowers in water hyacinth are larger and more attractive to pollinators due to higher resource allocation.
- Clonal integration stabilizes floral traits by mitigating resource variability, especially under stress.
- Isolated or defoliated plants show reduced floral traits, particularly in distal flowers.

## Abstract

In this study, we explored how the position of flowers and the connection between plant parts affect the development of individual flowers in water hyacinth (Eichhornia crassipes). This plant is known for its invasive ability and unique clonal growth, where new plants form from parts of the parent. We aimed to understand if this clonal connection helps stabilize flower traits when resources are limited. We found that flowers at the bottom of the plant receive more resources, making them larger and more attractive for pollinators. When this clonal connection was removed or the plants were stressed, flower size and pollinator-attracting traits decreased, especially in flowers located higher on the plant. These findings suggest that clonal integration helps water hyacinths maintain reproductive traits even in challenging conditions, possibly aiding their spread. This research offers insights into how plants adapt to varying environments, which could help in managing invasive species like water hyacinth.

Intra-individual variation in floral traits is linked to plant fitness, playing a central role in sexual selection. This variation can arise from architectural constraints, such as flower position on the inflorescence axis, and from environmental factors. In relation to the environmental influences on floral traits, the most common causes of variation are linked to the presence of pollinators, to plant resource acquisition strategies and to the availability of local resource pools. We investigated how clonal integration and resource depletion through defoliation affect floral trait stability in Eichhornia crassipes, testing whether clonal integration buffer floral traits against resource limitations. Using greenhouse experiments, we manipulated clonal structure and resource availability. We assessed the effects of floral position and clonal integration on floral traits through model selection. Our results showed that basal flowers generally had larger traits, more attractive to pollinators, and isolated or defoliated ramets exhibited significant reductions in floral traits, especially at distal flowers. Clonal integration stabilized floral traits across positions by mitigating the effects of resource variability. Clonal integration in E. crassipes enhances resilience to resource depletion, likely contributing to this species invasiveness. These findings highlight the significance of clonal and architectural integration in sustaining reproductive traits under environmental stress.