Secretory structures in Polygala section Timutua DC. (Polygalaceae)

Anatomy; Fabales; Polygaleae; taxonomy.

Polygala section Timutua DC. is one of the most representative sections within the genus Polygala L. including about 175 species. For the delimitation of the section, the yellowish glands or crocea are defined as diagnostic characters, however, there is no more complete information about their nature, such as the morphological and anatomical definitions of what they are, being characterized only by their yellow color. In addition, from previous observations there are indications of the existence of other glandular types not reported for the section. In this context, detailed anatomical studies with a significant sample number can produce new taxonomic and systematic interpretations about the glands, with comprehensive information on ontogeny, structure, type of substance secreted by the glands, allowing to relate such structures to a possible function, in addition to add more consistent information to the section. The main objective of this research project is to carry out an inventory of existing glands in the floral parts, fruit, leaf blades and stem of representatives of Polygala section Timutua occurring in Brazil, providing morphoanatomical information relevant to the systematics and taxonomy of the group, in addition to carrying out the evolutionary mapping of structures from phylogenetic studies. To carry out the work, 58 species were sampled so far, from Brazilian and international herbaria representing the Timutua section and related groups, P. sect. Clinclinia DC., P. sect. Monninopsis A.Gray, the genera Hualania Phil. and Muraltia DC., where initially leaf blades at different stages of development went through the herborization reversal process and subsequent treatments were destined for light microscopy. Preliminary results indicate that for the Timutua section 43 species present glands in different phases, for the species that represent the outgroups they were not observed. Anatomically, glands can be defined as cavities, ducts and anastomosed ducts with secretory activity, which suggests different types and origins for the structures.