Capturing variation in floral shape: a virtual3D based morphospace for Pelargonium

Area of Science:

• Botany
• Evolutionary Biology
• Geometric Morphometrics

Background:

• Floral shape variation is key to evolutionary studies.
• Previous research often overlooked three-dimensional (3D) floral shape.
• A novel method is needed to quantify complex floral morphology.

Purpose of the Study:

• To introduce and validate a virtual 3D geometric morphometrics approach for quantifying floral shape.
• To demonstrate the method's effectiveness in capturing comprehensive shape variation.
• To compare 3D morphospace with traditional 2D methods.

Main Methods:

• Reconstruction of virtual 3D floral models from 2D photographic data.
• Application of geometric morphometrics using 117 landmarks.
• Analysis of 90 diverse *Pelargonium* species (Geraniaceae).

Main Results:

• The virtual 3D method accurately represents floral shape, showing congruence with 2D datasets.
• Significant floral shape variation was observed both between and within *Pelargonium* species.
• Incorporating the third dimension is essential for a complete understanding of floral shape variation.

Conclusions:

• Virtual 3D geometric morphometrics provides a robust tool for floral shape analysis.
• This method overcomes limitations of 2D approaches, capturing more comprehensive morphological data.
• The study highlights the importance of 3D data for evolutionary interpretations of floral diversity.