Colleters in American Spermacoceae Genera (Rubiaceae): Morphoanatomical and Evolutionary Aspects

Abstract

Editor: Maria von BalthazarPremise of research. The primary goal of this study is to describe the colleters on vegetative and reproductive organs in the Spermacoceae tribe and to characterize their morphoanatomy, their distribution, and some functional and evolutionary aspects.Methodology. The anatomy, development, and vascularization of colleters from 28 species were studied using standard light and scanning electron microscopy based on fresh and fixed material. Our results are interpreted within the framework of recent molecular phylogenies.Pivotal results. Standard-type colleters were found on stipules, calyx, and bracteoles, and they were also found on underground buds in five species of Galianthe. Six species have green colleters, and two have vascularized colleters. We discuss previously unknown functional aspects based on the Staelia glandulosa colleters and propose a new term: long-lived colleters.Conclusions. This article describes the anatomy of colleters in the Spermacoceae tribe of the family Rubiaceae in detail. The presence of underground colleters in Galianthe grandifolia is confirmed and extended to other species of the genus. Vascularization is recorded for the first time in colleters of Mitracarpus and Staelia. This study provides data about the type, distribution, and anatomy of colleters in Spermacoceae, contributing important information for ongoing phylogenetic studies in the tribe. The proposal of a new functional type of colleter based on anatomical, morphological, and ecological aspects, named long-lived colleter, reflects the need to perform further comprehensive studies based on multidisciplinary approaches.

Deep in the Jelly: Histochemical and Functional Aspects of Mucilage-Secreting Floral Colleters in the Orchids Elleanthus brasiliensis and E. crinipes

“…Colleters have been described in at least 60 families of angiosperms (Thomas, 1991), including Apocynaceae (Appezzato-da-Glória and Estelita, 2000; Martins et al, 2013; Ribeiro et al, 2017), Bromeliaceae (Ballego-Campos and Paiva, 2018a,b), Euphorbiaceae (Vitarelli et al, 2015, 2016; Feio et al, 2016; Martins et al, 2016), Fabaceae (Paiva and Machado, 2006; Oliveira and Isaias, 2010), and Rubiaceae (Judkevich et al, 2017; Paiva-Pinheiro et al, 2019). These secretory structures are located in the vegetative and floral buds, and remain in these plant organs throughout their life.…”

Rubus alutaceus (Rosaceae), a new species for Colombia with agronomic potential

“…2) Reproductive morphology: flower: type, color, phytography, position of the gynoecium, symmetry, type of calyx and corolla, type of inflorescence; fruit: external color, shape; Seeds: number, shape, size and type of surface. The minimum and maximum values registered in the individuals collected were taken into account (STEARN, 1996;MORENO, 1984;FONT-QUER, 2001;BECERRA et al, 2002;RAMÍREZ and GOYES, 2005;JUDKEVICH et al, 2017).…”

A New Species of Randia (Rubiaceae) and the Taxonomic Significance of Foliar Anatomy in the Species of Randia of the Southern Cone of America

“…(Tresmondi et al 2015). This type of colleter has also been found in several species of the tribe Spermacoceae (Rubiaceae, Judkevich et al 2017), and in the Gentianaceae Macrocarpaea obtusifolia (Griseb.) Gilg.…”

“…Taking into account their morpho-anatomy, the stipular colleters of Randia heteromera belong to the standard type according to the classification of Lersten (1974aLersten ( , 1974b for the Rubiaceae, the same type as found in the other species of Randia (Judkevich et al 2015). Their ontogeny demonstrates that these secretory structures are emergences (Hallé 1967;Dave et al 1988;Thomas 1991;Coelho et al 2013;Muravnik et al 2014;Judkevich et al 2017). Recently, green stipular colleters have been mentioned in other species of the tribe Gardenieae, such as Cordiera concolor (Cham.)…”

“…According to recent studies carried out in the Rubiaceae, the colleters in this family can be found in the calyx (in the interlobular sinus, on the margin of the lobes and at the base of the internal face of the lobes), bracteoles, stipules (on the margin and internal face), and even on reduced laciniae on underground buds (Judkevich et al 2017). In Randia, the colleters are distributed on the inner surface at the base of the stipule.…”