3 Leaves

Premise: Morphometric analysis is a common approach for comparing and categorizing botanical samples; however, completing a suite of analyses using existing tools may require a multi-stage, multi-program process. To facilitate streamlined analysis within a single program, Morphological Analysis of Size and Shape (MASS) for leaves was developed. Its utility is demonstrated using exemplar leaf samples from Acer saccharum, Malus domestica, and Lithospermum.

Methods: Exemplar samples were obtained from across a single tree (Acer saccharum), three trees in the same species (Malus domestica), and online, digitized herbarium specimens (Lithospermum). MASS was used to complete simple geometric measurements of samples, such as length and area, as well as geometric morphological analyses including elliptical Fourier and Procrustes analyses. Principal component analysis (PCA) of data was also completed within the same program.

Results: MASS is capable of making desired measurements and analyzing traditional morphometric data as well as landmark and outline data.

Discussion: Using MASS, differences were observed among leaves of the three studied taxa, but only in Malus domestica were differences statistically significant or correlated with other morphological features. In the future, MASS could be applied for analysis of other two-dimensional organs and structures. MASS is available for download at https://github.com/gillianlynnryan/MASS.Easy leaf area is free, open source, software that rapidly measures leaf area in digital images (photographs or scanner images). Easy leaf area uses the RGB value of each pixel to identify leaf and scale regions in each image. After analysis, each highlighted image is written in tiff format to the ‘write folder’. A file named ‘leafarea.csv’ with image names, leaf pixel counts, scale pixel counts, and leaf area in cm^2 is also written to the ‘write folder’. Multiple leaves can be measured in the same image