Autorotating dispersal units of Getonia floribunda Roxb. (Combretaceae): Morphology, aerodynamics and geometrical significance
Data files
Sep 29, 2025 version files 38.42 KB
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Code_for_statistical_analysis-NJB-04882.txt
31.33 KB
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Data_for_Statistical_analysis_NJB-O4882.csv
3.60 KB
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README.md
3.48 KB
Abstract
Dispersal units that continuously rotate while falling purely due to aerodynamic forces are called autorotating dispersal units. Single- to multi-winged forms of autorotating dispersal units occur in nature. The dispersal unit of Getonia floribunda Roxb. (Combretaceae) is an example of a multi-winged whirling diaspore that performs efficient autorotation in the air during wind dispersal. The present study aims to investigate the diaspore morphology, geometry, underlying principles, and reasons for the specificity of its autorotation during dispersal, and to find the morphological variations and geometrical significance. Plants and their diaspores from four locations in Northern Kerala, South India, were selected for this study. Detailed macromorphological, micromorphological, developmental, anatomical, aerodynamic, and experimental studies were performed on the collected diaspores. The results show that fruit diaspores with a distinct spatial configuration of persistent cyclically arranged tepals (perianth whorl) and distribution of the centre of mass along the middle vertical axis are the reasons for vertical autorotation or helicopter motion. Wing modification and paper model experiments prove that the wings have an intrinsically predetermined geometrical right-side leading-edge curvature, which is the reason for their distinct anticlockwise direction during autorotation. A significant variation in the morphological parameters of these diaspores was observed across locations. Still-airdrop tests and further statistical analysis show that the ing fold angle developed due to the distinct spatial configuration of the wings exhibited a significant, predictable relationship with descent rate and terminal velocity in this diaspore across locations. Thus, wing geometry has an impact on flight in these diaspores and demonstrates the relationship between the shape and fitness of natural flight organs.
Dataset DOI: 10.5061/dryad.k98sf7mm3
Description of the data and file structure
The data was collected from dispersal units of four different locations in Northern Kerala, South India. Morphological measurements were carried out in the laboratory, and falling behaviours (descent rate, flipping or transition time, rotating time, and terminal velocity) were measured by conducting an experimental study, namely, the still-airdrop test explained by Seter and Rosen (1992), on samples from four locations separately. Then statistical analysis such as one-way ANOVA of morphological parameters such as weight, area, length, width, wing fold angle, and wing loading across samples of four location were performed to find any significant inter-location difference in morphological parameters; then bivariate correlation and multiple linear regression analysis were performed to find the significant factors affecting the descent rate and autorotation in this diaspore across locations. Regression and correlation analysis were performed using SPSS v20 (IBM) software, and all the data related to this analysis are incorporated in the manuscript and supplementary file itself. ANOVA and other statistical plots provided in the manuscript are done using the R software. The data codes used for this R analysis are provided here.
Files and variables
File 1: Data_for_Statistical_analysis_NJB-O4882.csv
Description: 1. Table of data for statistical analysis: data used for performing statistical analysis were provided in tabular form. First column of table includes name of locations; second column include sample numbers in each location; third column with weight of each diaspore in milligram; fourth column include the area of wings of the diaspore in millimeter square; fifth and sixth column with length and width of wings of diaspore in millimeter; seventh column include the fold angle of wings of each diaspore; eight column provided the wing loading of each diaspore were calculated by dividing weight of the diaspore in milligram divided by area of the wings in millimeter square; ninth column provided the descent rate (it is the distance travelled per second) of each diaspore during falling in meter per second; tenth column include the flipping time or time taken to change initial orientation of each diaspore in second; eleventh column include the time taken by each diaspore for autorotation in seconds and column twelve include the terminal velocity (it is the continuous fall rate in autorotation) of the diaspores in meter per second.
File 2: Code_for_statistical_analysis-NJB-04882.txt
Description: 1. ANOVA codes: R Codes used for performing ANOVA of weight, area, length, width, wing fold angle, and wing loading across samples of four locations.
2. Correlation plot codes: R codes used for performing correlation and preparation of a multi-panel plot within a grid of four location samples.
3. Regression plot codes: R codes used for performing regression analysis and preparation of a multi-panel plot within a grid of four location samples.
Code/software
The code provided in the data file can run by using R, version 4.5.1 (R Core Team 2025). The additional packages needed for running this code in R are ggplot2, dplyr, patchwork, a nd ggpubr.