Development, structure and senescence of colleters in Gardenia lucida Roxb. (Rubiaceae)

Abstract

Colleters are found on the adaxial basal part of the stipule and calyx of <em>Gardenia lucida</em>. They secrete a yellow transparent resinous substance commonly known as "Dikamali gum". They develop on both the stipule and calyx from a group of epidermal and hypodermal initials. A mature colleter consists of a central core of elongated parenchymatous cells surrounded by a palisade-like secretory epidermis. Druses type crystals of calcium oxalate are frequent in the colleters. At the time of senescence the central cells show lignification and the presence of tannin.

Foliar colleters inMacrocarpaea obtusifolia(Gentianaceae): anatomy, ontogeny, and secretion

“…The senescent process of M. obtusifolia colleters, which begins at the apex and extends to the base of the secretory portion, has been reported as common in other species of Aquifoliaceae (González and Tarragó 2009), Apocynaceae (Dave et al 1987;Thomas et al 1989;Thomas andDave 1989a, 1989b;Appezzato-da-Glória and Estelita 2000), and Rubiaceae (Dave et al 1988). In some species, the colour change in colleters has been associated with the initiation of senescence (Thomas and Dave 1990;Thomas 1991;Appezzatto-da-Glória and Estelita 2000;Barreiro and Machado 2007) and with the presence of phenolic compounds in the secretion (Thomas et al 1989;Martins 2012).…”

“…The presence of colleters is one of the synapomorphic characteristics of the order Gentianales, which includes the families Gentianaceae, Apocynaceae, Gelsemiaceae, Loganiaceae, and Rubiaceae . Many studies on types of colleters were performed with representatives from the Gentianales, especially from the Apocynaceae (Dave et al 1988;Thomas and Dave 1989b;Simões et al 2004;Martins et al 2010, Martins 2012 and Rubiaceae (Lersten 1975;Thomas 1991;Barreiro and Machado 2007;Machado et al 2012). Calycine colleters have been reported in different genera of Gentianaceae (Renobales et al 2001;Mészaros et al 2002;; however, reports of the presence of foliar colleters and studies of the anatomy and chemical nature of the secretion are scarce and restricted to species of the genera Gentiana L., Gentianella Moench, Gentianopsis Ma, Comastoma Toyok., Swertia L. (Renobales et al 2001), Calolisianthus Gilg (Delgado et al 2011), and Curtia Cham.…”

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

“…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.)…”

MORFO-ANATOMIA DO XILOPíâ??DIO DO GEOARBUSTO Galianthe grandifolia E.L. Cabral (RUBIACEAE) E A OCORRíÅ NCIA INCOMUM DE COLÉTERES SUBTERRíâ??NEOS.

“…Coléteres são relatados para a região nodal e estipular em espécies de Rubiaceae, mas apresentam uma localização mais diversificada em outros grupos de plantas, podendo ser encontrados nas folhas, brácteas, bractéolas, cálices e corolas (Thomas, 1991;Barreiro & Machado, 2007;Gomes et al, 2008 (Fahn, 1979;Thomas, 1991). A presença de coléteres é comum em Rubiaceae, principalmente na superfície adaxial das estípulas foliares (Solereder, 1908;Horner & Lersten, 1968;Van Hove, 1972;Lersten, 1974b;Thomas, 1991), podendo ser encontrados em pecíolos (Johansson, 1987), no cálice (Dave et al, 1988;Barreiro & Machado, 2007), em brácteas, bractéolas e corola Há relatos de emergências do tipo coléter medindo 1 mm (Rio et al, 2002;Schwarz & Furlan, 2002) e até mais de 2,6 mm (Lersten, 1974b), mas o comprimento dos coléteres examinados (150-450 µm) está dentro da faixa mais comumente relatada na literatura sobre estas estruturas (Miguel et al, 2006;Paiva & Machado, 2006;Barreiro & Machado, 2007).…”