Secretory Structures of Subterranean Organs of Some Species of the Cardueae, and Their Diagnostic Value

Abstract

Secretory ducts and cavities of roots and rhizomes are typical features of the Cardueae tribe in the Asteraceae family. We used light microscopy to analyze the anatomy of the subterranean organs of 21 species of 13 genera of the Cardueae, with particular attention to the secretory system, interpreted in taxonomic terms. The anatomy of secretory ducts varied greatly. A new measurement quotient, C1 [length of epithelial cells (longitudinal section)] and C2 [length of adjacent cells (longitudinal section)] was established. Different types of ducts are described based on type of development and the size ratios among epithelial cells. Detailed anatomical descriptions of the ducts are given, together with their occurrence in particular taxa. The simultaneous presence of various secretory ducts within a single species and their spatial position relative to other prominent anatomical features provide valuable characters for discriminating the studied Cardueae species. These analyses are of particular interest for identification of herbal drugs as, besides chemical analytical techniques such as chromatographic fingerprinting, light microscopy is a common method for purity controls and thus required in official pharmacopeias.K Ke ey y w wo or rd ds s: : Root anatomy, microscopy, Asteraceae, Cardueae, secretory ducts.

The role of fibres and the hypodermis in Compositae melanin secretion

“…After the lignification of the fibre cell walls, there was the further production of vesicles, having an electron-dense amorphous content that was restricted to the periphery of the vesicle, which were secreted primarily at the junction of the fibres with the hypodermis. Another argument against a role for the hypodermis in the secretion of phytomelanin is that the presence of this pigment is not associated with the hypodermis in the roots and rhizomes of some species of the Centaurea tribe (Cardueae; Fritz and Saukel, 2011) and the fruits of Bishopalea, Heterocoma, Sipolisia and Xerxes (Vernonieae; Loeuille, 2011). These observations reinforce the notion that the fibres are responsible for the secretion of phytomelanin in P. diffusa.…”

“…It is believed that the adaptive value of phytomelanin is related to the protection of the fruit against predation (Johnson and Beard, 1977). However, it is possible that the occurrence of phytomelanin has been underestimated in the family, as there are recent reports of its presence in the vegetative organs of tribe Cardueae (Fritz and Saukel, 2011).…”

Anatomy and essential oil composition of the underground systems of three species ofAldamaLa Llave (Asteraceae)1

“…Another important feature of the underground systems of Asteraceae species is the presence of structures secreting secondary metabolites (Appezzato-da-Gló ria et al 2008b, Cury and Appezzato-da-Gló ria 2009, Fritz and Saukel 2011, Oliveira et al 2013. Several compounds have already been described for Aldama (5 Viguiera), including sesquiterpene lactones and diterpenes with known biological activity (Da Costa et al 1996, Marquina et al 2001, Spring et al 2003, Nicolete et al 2009.…”

Can climate and soil conditions change the morpho-anatomy among individuals from different localities? A case study in Aldama grandiflora (Asteraceae)

“…Leaves characters such as the type and position of secretory structures have been useful for species differentiation (Castro et al, 1997;Fahn, 2000;Oliveira et al, 2013), including in Asteraceae (Solereder, 1908;Metcalfe and Chalk, 1950;Wagenitz, 1976;Castro et al, 1997;Adedeji and Jewoola, 2008;Fritz and Saukel, 2011). However, some studies (Kakrani et al, 1991;Sheue et al, 2003;Filartiga et al, 2016) showed that the number and position of secretory ducts can vary, rendering it difficult to use this character as the only parameter of differentiation among species.…”