First report of ultra-sculpturing and taxonomic implications of seed morphology of selected genus Euphorbia L

Abstract

The genus Euphorbia L. characterizes a diverse and ubiquitous range of flowering plants across numerous habitats worldwide. The study aimed to resolve the taxonomic significance of seed morphology across 31 species within Euphorbia L. Qualitative and quantitative micro and macromorphological characteristics of seeds and caruncles were studied using both stereomicroscopy and scanning electron microscopy. The results of the study showed variation in seed characteristics such as size, shape, color, surfaces, and caruncle characteristics. These characteristics are often constant and useful in identification and classification in Euphorbia species. Seed surfaces represented variation from reticulate, gemmate, clavate, psilate, foveolate, verrucate, chinate, reticulate, baculate, scabrate, and striate among studied taxa. Additionally, rugose, reticulate, verrucose, acute, and scabrate surfaces were investigated in caruncle of studied taxa. Moreover, some taxa are caruncle free. The morphometric variation of the seeds among the studied taxa was analyzed using the unweighted pair group method with arithmetic mean (UPGMA) and principal component (PCA) analyses. The dendrogram and plot results from the cluster and PCA analyses showed that Euphorbia taxa were grouped into two major clusters. Stereo and Scanning electron micrographs are provided for all known studied taxa.