Abstract Colleters are glandular structures related to young shoots protection. In several Angiosperm families, as in Rubiaceae colleters are taxonomically important. This study reports presence, location, morpho-anatomical structure, ontogeny and histochemistry of colleters in vegetative and reproductive organs in 6 species of Cephalanthus and 20 species representatives of the tribe Naucleeae. Primarily based on their color and their secretion color, they were classified into light (LC) and dark (DC) colleters. The LC are exclusive to the inner side of the stipule, while the DC are found in several vegetative and reproductive organs. Histochemical studies revealed that higher mucilage and phenol content in DC could explain the dark color secretion. Results were analyzed at genus, tribe and subtribe levels, evidencing the taxonomic relevance in the family. Finally, the presence of corolline colleters in angiosperm flowers was reviewed. It was confirmed that, besides Cephalanthus, they are only present in Adenoa (Passifloraceae) and Chamaecrista (Fabaceae). Therefore, structures described as colleters in Nerium (Apocynaceae) and Cuscuta (Cuscutaceae) corollas do not correspond to colleters. This proves that corolline colleter is a rare character in Angiosperms. To conclude we provide a record of presence/absence, type and distribution of corolline colleters in an Angiosperm phylogenetic tree.

The genus Bulbostylis Kunth includes about 150 species that inhabit tropical and subtropical areas worldwide. In Bulbostylis, as in other kinds of sedges, the exomorphology of fruits is one of the steadiest characters for infrageneric classification. This research was focused on evaluating achene micromorphology in twenty Bulbostylis species of Southern America (Argentina, Chile, Paraguay, Uruguay and Paraná, Santa Catarina and Rio Grande do Sul in Brazil). Based on studies with optical and scanning electron microscopy, several groups are proposed, considering the micromorphology of the achenes and presence and type of silicophytoliths. Chemical microanalysis of fruits with EDX/MEB was also performed. The description system based on exomorphological characters, applicable to fruits and seeds, is updated.

El género Bulbostylis Kunth incluye aproximadamente 150 especies que habitan zonas tropicales y subtropicales en todo el mundo. En Bulbostylis, al igual que en otros géneros de Ciperáceas, la exomorfología de los frutos es uno de los caracteres más estables para la clasificación infragenérica. En este trabajo se dan a conocer la micromorfología y estructura de los frutos de Bulbostylis para veinte especies de América Austral, representadas en Argentina, Brasil (Paraná, Santa Catarina y Rio Grande do Sul), Chile, Paraguay y Uruguay. En base a estudios con microscopía óptica y electrónica de barrido se proponen agrupamientos, teniendo en cuenta la micromorfología de los aquenios así como la presencia y tipo de silicofitolitos. También se realizan microanálisis químicos de los frutos con EDX/ MEB. Se actualiza el sistema de descripción basado en caracteres exomorfológicos, aplicable a frutos y semillas.

ABSTRACT The genus Oldenlandia (Rubiaceae) has a conflicting generic delimitation, with representatives that show different floral syndromes. Oldenlandia salzmannii is a marshy herb that is widespread in South America. It is heterostylous, specifically distylous, and self-compatible. Recent molecular phylogenetic studies found that this species forms a clade that is isolated from the remaining described taxa of Oldenlandia. Information about the floral anatomy and reproductive biology of genera in the Spermacoceae tribe, particularly Oldenlandia, is insufficient, especially among the neotropical species. Accordingly, the present study aimed at contributing information on the reproductive biology of Oldenlandia salzmannii by analyzing its floral morpho-anatomy, morphometrics and phenology of both floral morphs. These analyses were conducted with natural, cultivated and fixed material using optical and scanning electron microscopes. Morphologically, the species is typically heterostylous with two floral morphs, long-styled and short-styled, the main difference being the indument of the corolla. The short-styled flowers have larger anthers and pollen grains. Morphometrics show a high degree of herkogamic reciprocity. The mature ovules have a hemitropous position, which is the first record of this position for the Spermacoceae tribe. This study represents the first comprehensive morphological study of Oldenlandia salzmannii.

This paper deals with the study of leaf domatia in Argentine Rubiaceae, which are common morphogenetic structures on the underside of the leaves of woody plants, which can establish mutual relations with mites or ants. Tufts of hair, pockets, cavities and crypts: many families are classified into types common relatively well preserved. Around 290 families of “dicots” have domatia, Rubiaceae being the best represented with all known and transitional types. Domestic classification by molecular data, Rubiaceae divided into three subfamilies: Rubioideae, Ixorideae and Cinchonoideae. In Argentina inhabit 41 genera and 132 species of Rubiaceae, of which 34 are woody (27%). As result, tree domatia types were found: tuft of hair, pockets and crypt, present in 14 species of Rubiaceace. It is mentioned for the first time a domatia in a vine species of Manettia. The results were compared with recent molecular studies; this confirmed the plesiomorphic condition thereof, since different types are common to the three subfamilies almost all the tribes of the family. Based on this sampling, the following tribes completely lack domatia: Anthospermeae, Rubieae, Paederieae and Pavetteae.

Este trabajo estudia los domacios foliares en Rubiáceas argentinas, los cuales son estructuras morfogenéticas frecuentes en el envés de las hojas de plantas leñosas, que permiten establecer relaciones mutualistas con ácaros u hormigas. Se clasifican en tipos relativamente bien conservados comunes a numerosas familias: mechones de pelos, bolsillos, cavidades y criptas. Alrededor de 290 familias de “dicotiledóneas” tienen domacios, siendo Rubiaceae la mejor representada con todos los tipos conocidos y transicionales. La clasificación intrafamiliar según datos moleculares, divide a Rubiaceae en tres subfamilias: Rubioideae, Ixorideae y Cinchonoideae. En Argentina viven 41 géneros y 132 especies de Rubiáceas, de las cuales 34 son leñosas (27%). Como resultado se encontraron tres tipos de domacios: mechón de pelos, bolsillos y en cripta en 14 especies de Rubiáceas. Se menciona por primera vez domacios en una enredadera sufrútice de la familia, en el género Manettia. Los resultados obtenidos fueron contrastados con estudios moleculares recientes, lo que permitió confirmar la condición plesiomórfica de los mismos, ya que los diferentes tipos son comunes a las tres subfamilias y a casi todas las tribus de la familia. Basado en el presente muestreo, las tribus Anthospermeae, Rubieae, Paederieae y Pavetteae carecen completamente de domacios.

A morphological and anatomical analysis of Schinopsis balansae Engl. was performed, using optical and scanning electron microscopy. The main objective was to obtain data from the flowers of this species, usually described as polygamous-dioecious. The results shows that the flowers described as functionally perfect are structurally pistillate; although have five staminoids, they are smaller and lack sporogenous tissue. In the staminate flowers, the structure described as vestigial pistil is the excrescence of the apex of the receptacle, covered by nectariferous tissue. Thus, it is right to describe S. balansae as dioecious species. The study of the vascularization of male flowers shows that the reduction process is complete, since not even the vascular traces for the pistil persists. The gynoecium of pistillate flowers is pseudomonomerous with one functional carpel, one ovule and one dorsal style and stigmata, and two vestigial carpels, represented only by individual lateral style/stigma. Both types of flowers present an intrastaminal nectary disc, with nectarostomatas for nectar release. The analysis of the anatomic structure of S. balansae provides data that are consistent with those found in other studied genus of Anacardioideae group in the Anacardiaceae family.

Se realizó el análisis morfo-anatómico de Schinopsis balansae Engl. con microscopía óptica y electrónica de barrido a fin de obtener datos de las flores de esta especie, definida como polígamo-dioica. Los resultados muestran que las flores estructuralmente perfectas son funcionalmente pistiladas, si bien presentan cinco estaminodios, los mismos carecen de tejido esporógeno; mientras que en las flores estaminadas la estructura denominada pistilo vestigial no es más que la excrecencia del ápice del receptáculo, cubierta por tejido nectarífero. De este modo, lo correcto es describir S. balansae como especie dioica. El estudio de la vascularización de las flores estaminadas muestra que el proceso de reducción es completo, ya que ni siquiera persisten los haces vasculares del pistilo. El gineceo de las flores pistiladas es pseudomonómero, con un carpelo funcional, un estilo/estigma dorsal y un óvulo; además posee dos carpelos vestigiales representados por sendos estilo/estigma laterales. Ambos tipos de flores presentan un disco nectarífero intraestaminal, con nectarostomatas para la salida del néctar. El análisis de la estructura anatómica de S. balansae brinda datos que concuerdan con los encontrados en otros géneros estudiados de la subfamila Anacardioideae de la familia Anacardiaceae.

Some morphological characters of seeds are important in taxonomy of the Turneraceae family, and have been used to distinguish genera and species. However their anatomy has been studied only in a few species. The seeds of Piriqueta and Turnera, the most numerous genera of the family were analyzed -including all the series of the last one- in order to fulfill the information about development and variation of the morph-anatomical characters. The goals were to depict and circumscribe the variants, to check their taxonomic value. The anatomy of ovules is alike in all analyzed species. The integuments are not multiplicative, the outer one makes up the seed testa, with two layers, and the inner integument develops the tegmen with three layers. The seed coat basic structure is composed of areoles (made up by the giant cells of endotesta) delimited by muri (set out by exotegmen sclereids). Some species of Turnera and Piriqueta have one or two dot-like hollows in each areole, set up by protrusions of the endotesta cells with labyrinth walls on the inner face. The seed coat shows two basic types: reticulate and crested. According to the degree of development of transverse muri, the reticulate type shows two subtypes. The most common is the reticulate subtype, found in Piriqueta and in several series of Turnera. The striate-reticulate subtype, with transverse muri hardly visible, is found in species of some series of Turnera. The crested seed coat, found exclusively in T. sidoides, comes out when groups of exotesta cells grow developing crests of different height, which cover and hide the basic design. In many species of Piriqueta, the exotesta shows finger-like papillae while in Turnera it displays other types of papillae. The aril is inserted around the hilum in Piriqueta and in most species of Turnera, but in two species of series Anomalae and two of subseries Umbilicatae it is inserted also along the basal segment of the raphe. Turnera includes 66% of the species of the family, and in agreement it shows the towering diversity in seed morphology.

Algunos caracteres morfológicos seminales tienen importancia taxonómica y han sido usados para diferenciar géneros y especies en la familia Turneraceae. Sin embargo, su anatomía fue estudiada en pocos taxones. Se analizaron las semillas en los géneros más numerosos de la familia: Piriqueta y Turnera, incluyendo todas las series del último, a fin de completar la información acerca del desarrollo y variantes de los caracteres morfo-anatómicos. Los objetivos fueron caracterizar y constatar su valor taxonómico. Los óvulos presentan anatomía semejante en todas las especies analizadas. Los tegumentos seminales no son multiplicativos, el externo constituye la testa de la semilla, con dos capas de espesor, y el interno forma el tegmen triestratificado. La estructura básica de la cubierta seminal está integrada por aréolas (formadas por células gigantes de la endotesta) limitadas por muros (constituidos por esclereidas del exotegmen), cubiertas por la exotesta, que puede ser lisa o crestada. Algunas especies de Turnera y Piriqueta tienen depresiones punctiformes en las aréolas, solitarias o dobles, determinadas por protrusiones de las células endotestales con paredes laberínticas en la cara interna. La cubierta seminal presenta dos tipos básicos: crestado y reticulado con dos subtipos según el desarrollo de los muros. El subtipo reticulado aparece en Piriqueta y varias series de Turnera; el subtipo estriado-reticulado, con muros transversales poco visibles, en especies de algunas series de Turnera. La cubierta seminal crestada, exclusiva de T. sidoides L., se forma cuando las células de la exotesta producen crestas de altura diversa que enmascaran el diseño subyacente. En muchas especies de Piriqueta la exotesta presenta papilas digitifomes, mientras en Turnera aparecen otras papilas. El arilo es hilar en Piriqueta y en la gran mayoría de las especies de Turnera; dos especies de la serie Anomalae y dos de la subserie Umbilicatae presentan arilo ráfico. El género Turnera incluye el 66% de las especies de la familia, y en concordancia, es el que ofrece mayor diversidad en las semillas.

The aims of this work were to describe the morphology, anatomy and development of the fruits of 12 species of Piriqueta and 30 species of Turnera; to identify the structures related to the process of dehiscence of the capsule; and to verify the occurrence of standards carpological structure between the studied species. The ovary is 3-carpellar, syncarpous, unilocular with parietal placentation and has the same anatomical structure in all studied species. The outer and inner epidermises are single-layered with stomata; the ovarian mesophyll is composed by parenchyma, with three dorsal and three marginal vascular bundles. During the fruit development, the external epidermis develops a papillose epicarp in Piriqueta species. The mesocarp develops from the cells of the middle zone of the carpel. The mechanic stratum is formed by brachysclereids, developing from cells of the outer, median or inner layers of the ovarian mesophyll. Two main distributional patterns can be recognised: a mechanic stratum formed by continuous cylinder or clusters of brachysclereids. The first type determines smooth fruits, and the last form granular, verrucose, or tuberculate fruits. The capsules are loculicidal, with dehiscence lines characterized by the presence of macrosclereids, longitudinally dispose at the inner side of the carpellar dorsal bundle. We conclude that different types of pericarp are a post-fertilization feature, because the structure of the ovary is exactly the same in all species. We analyze the anatomy of the fruit in relation to the current taxonomic arrangement.

En este estudio se analiza la anatomía, estructura y desarrollo de los frutos en 12 especies de Piriqueta y 30 especies de Turnera; con el objetivo de identificar la estructura involucrada en la dehiscencia y verificar la existencia de patrones en la organización del fruto entre las especies analizadas. El ovario es sincárpico, tricarpelar, unilocular con placentación parietal, presentando la misma estructura en todas las especies. Ambas epidermis carpelares son uniestratificadas y tienen estomas, el mesófilo es parenquimático con 3 haces dorsales y 3 marginales. Durante el desarrollo del fruto, la epidermis externa forma un epicarpo papiloso en las especies de Piriqueta. El mesocarpio deriva de los estratos medios del ovario, formando un estrato mecánico de braquiesclereidas. Estas esclereidas pueden organizarse como un cilindro continuo determinando frutos de superficie lisa o agruparse en nidos, unidos o no, determinando así frutos granulares, verrugosos, o tuberculados. Las cápsulas son loculicidas, con línea de dehiscencia formada por macroesclereidas dispuestas longitudinalmente en el fruto, paralelas al haz carpelar dorsal. Se concluye que los diferentes tipos de pericarpio son un rasgo post-fecundación, dado que la estructura del ovario es exactamente la misma en todas las especies analizadas. Se analiza la anatomía del fruto en relación al esquema taxonómico actualizado.

The anatomical and morphological characters of the extrafloral nectaries were studied in 4 species of Piriqueta , and in 16 which belong to six of the seven series of Turnera (Turneraceae) that present these glands. They were classified according to its form and degree of development and a new type of "pore" was described: foveolate. Based on morpho-anatomical characters, a probable morphological sequence was proposed. This would locate the species with flattened EFN and without "pores" in a lower position; after that, the species with flattened nectaries and foveolate "pores" are found; in an intermediate position the elevated extrafloral nectaries (EFN) - sphericals or hemisphericals as well as cupuliforms -were found; finally, the cupuliform EFN with crateriform or mesetiform "pore" are found. Several species of diverse series presented variable characters, being located in an unlike position in the proposed morphological sequence; species with heterogeneous characters were also observed, being difficult to establish their location in the sequence.

Se estudiaron los caracteres anatómicos y morfológicos de los nectarios extraflorales en 4 especies de Piriqueta , así como en 16 incluídas en 6 de las 7 series de Turnera (Turneraceae) que presentan estas glándulas. Se los clasificó de acuerdo a su forma y grado de desarrollo y se describió un nuevo tipo de "poro": foveolado. Basada en caracteres morfo-anatómicos se propuso una probable secuencia morfológica que ubicaría en una posición inferior menos especializados a las especies con nectarios extraflorales (NEF) planos y sin "poros"; luego se encuentran las especies con nectarios planos y "poros" foveolados; en posición intermedia se encontrarían los NEF elevados, tanto globosos o hemisféricos como cupuliformes; por último, están los NEF cupuliformes con "poro" crateriforme o mesetiforme. Varias especies de diversas series presentaron caracteres variables, ubicándose en posición dispar en la secuencia morfológica propuesta; también se observaron especies con caracteres heterogenéos, siendo difícil establecer su ubicación en la secuencia.