Morphology, distribution, and histochemistry of secretory structures in vegetative organs of Santolina leucantha Bertol. (Asteraceae)

In the vegetative organs of Santolina leucantha Bertol. (Anthemideae), two distinct types of secretory structures are present: Internal secretory duct s and external glandular trichomes. The ducts are variable in morphology an d location, depending on the organ in which they are present. The trichomes , however, show the same structure everywhere. In the roots, there are also scattered cells rich in secretion that are distributed in the periphery of the cortical cylinder. The histochemical analysis of the secretion reveals the presence in all the vegetative organs of many important secondary comp ounds. Vegetative secretory structures are similar to those in the capitulu m we have described in a previous paper.