Fruits of neotropical species of the tribe Malveae (Malvoideae - Malvaceae): macro- and micromorphology

Abstract

Fruit morphology of the tribe Malveae has been discussed since the first taxonomic classifications of Malvaceae. The fruits are schizocarps, with some genera possessing an endoglossum. Besides morphological variation in the endoglossum, other differences include the number seeds per locule and ornamentation of the exocarp. An in-depth study of the fruit morphology of Malveae is essential to gain insight into the relationships among taxa of the tribe. Therefore, the present study aimed to describe the fruit morphology of Malveae, including micromorphology, variation in endoglossum structure and arrangement of seeds in the locule, to comprehensively evaluate the systematic relationships among its contained taxa. The results indicate morphological variation in fruit of various genera with regard to the number of mericarps, degree of dehiscence, relationship between calyx and fruit and their relative sizes, number and morphology of spines, number of seeds per locule, presence or absence of an endoglossum, presence and types of trichomes in exocarp and endocarp, and shape and presence of trichomes in the testa of seeds. Despite the morphological proximity of taxa, there are distinct combinations of characters that define some genera, and when one or more characters overlap, joint analysis makes it possible to clarify existing relationships.

Taxonomic significance of seed macro‐micromorphology of Turkish Alcea L. (Malvaceae) through light microscopy and scanning electron microscopy

“…The significance of seed morphological characteristics in plant systematics for the family Malvaceae has been emphasized in some studies (Ahmed & Qaiser, 1989; Ather et al, 2009; Kirkbride et al, 2006; Masullo et al, 2020; Özbek & Uzunhisarcıklı, 2020a; 2020b; Sivarajan & Pradeep, 1996). Paul and Nayar (1987) examined the seeds of 54 taxa under 17 genera using SEM, and said that the variation in the seed coat surface differs from species to species, even in infraspecific ranks.…”

Taxonomic characters of fruit, mericarp and seed of some Malvaceae species

“…Later, the dried seeds were transferred onto specimen stubs using double adhesive tapes, coated with a thin gold film using (JEOL JFC 1100E ionsputtering device), and examined with an electron microscope (JEOL ISM-IT200), at the Electron Microscope Unit, Faculty of Science, Alexandria University. The terminology used for describing the morphology of fruit, mericarp, and seed is in accordance with Khalik et al [17], Özbek and Uzunhisarcikli, [18 and 38], and Masullo et al [19]. For numerical analysis, PRIMER software (version 6.0) was used to generate a cluster analysis of the similarity matrix between the species under study to construct a dendrogram.…”

“…Mericarps and seeds of four species belonging to the genus Althaea L. (Malvaceae) were studied to identify their characteristics and importance as taxonomic evidence [18]. Macro-and micro-morphological characters of fruits in some species of the tribe Malveae were examined and established by [19]. Rao and Dave [20] and Bharati [21] studied the schizocarp fruit and mericarp of Sida species and considered the mericarp morphology a key character to determine the identity of the species.…”

Reproductive biology of Vatica venulosa Blume (Dipterocarpaceae)

“…Physiological maturity determination is carried out to determine the right harvest time with maximum seed viability, vigor and relatively low seed moisture content. Masullo (2020) states that there are variations in fruit morphology from the genera Malvaceae, including the number of mericarp, the relationship between calyx and fruit, the number of seed per locule. V. venulosa has fruit set 13.17-16.15%, while the research results of Keshavanarayan et al (2015) revealed that the fruit set of Vateria macrocarpa (Dipterocarpaceae) with natural pollination was 22%.…”