Leaf and sepal colleters in Calolisianthus speciosus Gilg (Gentianaceae): a morphoanatomical comparative analysis and mechanisms of exudation

Calolisianthus speciosus, an endemic species of cerrado and campos rupestres in Brazil, bears colleters both the leaf base sepal. These (leaf sepal) were anatomically compared to identify differences their structure secretion mechanism. Samples sepals leaves different development stages collected processed according standard methodologies for anatomical ultrastructural studies. Sepal similar, being non-vascularized, sessile or short-stalked composed a multicellular secretory head with large intercellular spaces where secretion, predominance protein polysaccharides, is accumulated. The cells have thin walls, dense cytoplasm granular endoplasmic reticulum, numerous dictyosomes mitochondria. characters are agreement production mucilaginous/protein secretion. secretion-filled vacuole merges plasma membrane releasing its contents periplasmic space it remains until release outside cell wall, accumulated formed by schizogeny. This accumulation generates pressure that promotes passage through external wall cuticle superficial colleter.