Revisión de Randia (Rubiaceae) en Argentina, taxonomía y morfoanatomía

Abstract

Se presenta una revisión de las especies argentinas de Randia. A partir de este estudio se reconocen tres especies: R. ferox, R. micracantha y R. calycina, siendo ésta última una nueva cita para el país. Se propone excluir del país a R. armata, especie amplia y erróneamente citada para el área. Se analizaron aspectos taxonómicos, la anatomía vegetativa y morfología polínica de las tres especies. Todos los taxones son descritos y diferenciados a través de una clave dicotómica. Se incluyen además imágenes de los caracteres diagnósticos de las especies, mapa de distribución y observaciones ecológicas. Se proponen lectotipos para los nombres de los taxones Basanacantha, R. calycina y R. ferox. Randia micracantha var. glabra es tratada como un nuevo sinónimo de Randia micracantha. Se determinó que algunos caracteres anatómicos y polínicos son útiles para la diferenciación de las especies argentinas.

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

“…The data collected here, and in previous studies (Judkevich et al 2015(Judkevich et al , 2016, show that R. brevituba, R. calycina, R. ferox, R. heteromera, and R. micracantha can be differentiated by the vascular system in their leaves, which is important when there is no material other than the vegetative (Fig. 7).…”

“…bundles (Metcalfe and Chalk 1950;Brouwer and Clifford 1990;Martínez-Cabrera et al 2009). Randia heteromera shares these general characteristics with the other species of Randia in the southern cone of America (Judkevich et al 2015). In addition, a particular feature was found in R. brevituba, notably that the middle vein of the foliar lamina presents adaxial stomata and the collenchyma in this zone is interrupted by chlorenchyma.…”

“…Taxonomy-Randia specimens are difficult to identify, especially when they only bear staminate flowers (sometimes without a corolla) or fruits. Additionally, most herbarium specimens are misidentified and often several species are classified under the same name, as already suggested in previous studies (Judkevich et al 2015(Judkevich et al , 2016. In our opinion, studies on the genus need seasonal observation of the plants in order to obtain both staminate and pistillate individuals.…”

“…In the Atlantic Forest species of Psychotria L. (Rubiaceae), the anatomy and micromorphology of the leaves of interspecific groups have been useful as diagnostic traits for the genus (Moraes et al 2011). In Randia calycina, R. ferox, and R. micracantha, the distribution of vascular tissue in the middle vein of the leaf is a diagnostic character that, together with others, helps to differentiate these species (Judkevich et al 2015).…”

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

“…The presence of colleters on the internal surface of the calyx and stipules is common in other tribes of the Rubiaceae, even in Rubioidae (e.g., on the stipules of Psychotria L., tribe Psychotrieae; Miguel et al 2009;Vitarelli and Santos 2009;Tresmondi et al 2015). The latter pattern is also found in Cephalanthus occidentalis L. of the tribe Naucleeae (Cinchonoideae; Rutishauser 1983) and in species of Gardenieae (Ixoroideae), such as Randia L. (Judkevich et al 2015;Tresmondi et al 2015). In other Gardenieae, the co-occurrence of colleters inside the stipules and calyx is very common, such as in Gardenia J. Ellis (Dave et al 1988;Low and Wong 2007), Cordiera A.…”