# “Amniotic fluid” in womb-like flower bracts protects floral development and promotes drought resistance in karst habitats

## TL;DR

A plant species uses a fluid-filled 'womb-like' structure to protect its flowers and survive in drought-prone karst environments.

## Contribution

The discovery of a plant using amniotic fluid-like structures to protect flowers and resist drought in karst habitats.

## Key findings

- Flower buds in Hemiboea magnibracteata are enclosed in fluid-filled bracts that protect against temperature extremes and desiccation.
- The fluid reservoir likely helps the plant resist drought and calcium stress in karst habitats.
- This strategy is analogous to amniotic fluid in mammals, offering new insights into plant adaptation.

## Abstract

Water serves diverse functions in plant growth and reproduction. Here, we report a novel strategy in the terrestrial karst plant Hemiboea magnibracteata analogous to amniotic fluid in mammals. Developing flower buds enclosed in ‘womb-like’ bracts are completely immersed in fluids and protected against excessive temperature and desiccation. The reservoir of water also likely limits drought and calcium stress in the highly specialized abiotic conditions of karst habitats.