The Cinderella discipline: morphometrics and their use in botanical classification

Abstract

Between the 1960s and the present day, the use of morphology in plant taxonomy suffered a major decline, in part driven by the apparent superiority of DNA-based approaches to data generation. However, in recent years computer image recognition has re-kindled the interest in morphological techniques. Linear or geometric morphometric approaches have been employed to distinguish and classify a wide variety of organisms; each has strengths and weaknesses. Here we review these approaches with a focus on plant classification and present a case for the combination of morphometrics with statistical/machine learning. There are many classification techniques available for biological analysis and selecting the most appropriate is not trivial. Performance should be evaluated using standardized metrics such as accuracy, sensitivity and specificity. The gathering and storage of high-resolution images, combined with the processing power of desktop computers, makes morphometric approaches practical as a time- and cost-efficient way of non-destructive identification of plant samples.

Comparing ant morphology measurements from microscope and online AntWeb.org 2D z‐stacked images

“…Modern morphological examination of organisms, particularly in biodiversity research, often requires quantitative, morphometric-based approaches (Lieber, 2021;Snodgrass, 2018). Indeed, morphometrics, one of the most widely used quantitative approaches to studying morphology, has long been a popular approach in taxonomy and systematics (e.g., Baur et al, 2014;Christodoulou et al, 2020;Johnson et al, 2018;Longino & Branstetter, 2020;Michaloudi et al, 2018;Wagner et al, 2017).…”

Seed Geometry in the Vitaceae

“…Morphology has not received the attention due in recent decades due to the increased emphasis on molecular approaches, but the importance of descriptive aspects is rising [ 68 ]. Seed morphology in particular may provide the basis for developments in Ecology and Evolution.…”

When do apples stop growing, and why does it matter?

“…In this study we explore whether these morphometrics stabilize earlier in the season. This is to ascertain whether fruit that has been picked prior to maturation can be included to train and test morphometric classification methods [ 26 ]. Here we focused on twelve cultivars, 6 of which we repeated for a second year, and studied size changes using four relevant morphometrics.…”