GONZALEZ Ana Maria
congresos y reuniones científicas
Colleters in Spermacoceae (Rubiaceae): distribution and morpho-anatomy description
MARINA D. JUDKEVICHNORDESTE ; ROBERTO M. SALAS ; ANA M. GONZALEZ
Salvador Bahía, Brasil.
Conferencia; VI International Rubiaceae and Gentianales Conference.; 2014
Colleters are secretory emergencies protecting the development organs of many families of Angiosperms, including Rubiaceae, in which has an uncertain taxonomic value. The distribution and the morpho-anatomy of colleters from 23 species belonging to 10 genera of the Spermacoceae tribe (Rubiaceae) were analyzed in order to state their taxonomic importance. Nodes with leaves, flower buds and flowers (23 sp.), and subterranean buds (4 sp.) were fixed and dehydrated using conventional techniques. The samples have analyzed with optical and scanning electron microscopy. Fresh samples were observed in some species. As result, the colleters are located in: 1) interlobular sinuses of calyx (20 sp.) in apex of fimbriae or stalk of varying complexity, 2) on edge of the stipular sheath (1 sp.) or on the apex of the stipular fimbriae (22 sp.), and 3) at the reduced fimbriae of underground buds (4 sp.). In all species the colleters are conical to tear-shaped. Anatomically have a parenchymatous axis, not vascularized, which can be contains packages of raphides. Surrounding the axis there is a palisade epidermis. According to previous classifications, it corresponds to the standard type. In three species, we observed also that the parenchymatous axis contains chloroplasts. As conclusion, the location and distribution of colleters, and the presence of chloroplasts in the axis are important taxonomic characters to distinguish the analyzed genera of Spermacoceae.