ИСТИНА

The synapomorphies of the inflorescence and flower structure in different monophyletic clades of Arecaceae are revealed based on the results of floral structure investigations in palm family. At the same time, the structure of fruits in a number of palm taxa are still not investigated, which make them actual particularly for understanding the histlogical and structural divercity of their pericarp. Of particular interest are the fruits of monotypic genera and local endemics, such as the endemic of Juan Fernandez Is. – Juania australis (Mart.) Drude ex Hook. fil. Its pericarp is differentiated into the exocarp (single-layered epidermis composed by the rectangular cells), multilayered mesocarp (80-90 cell layers) composed by thin walled cells, and the endocarp (single layer of palisade cells with thick lignified walled). The peripheral zone of the mesocarp is composed by 3-4 layers of small thin walled cells and there is a continuous belt of 2-4 layers of thick walled small brachysclereids below them. In the main zone of the mesocarp the numerous large tannin-containing cells and sclereids (sometimes in small clusters) of different shapes are scattered among the thin walled cells. The vascular bundles of different size are present in the mesocarp as well. Based on the anatomy the fruits of Juania are considers as pyrenarium of Ilex type, similar to other representatives of the tribe Ceroxyleae, except Oraniopsis with berries of Nymphaea type. The lignified single-layered palisade endocarp is also found on all other representatives of the subfamily Ceroxyloideae and in a several representatives of the subfamily Arecoideae and might represent a synapomorphy of these two subfamilies of palm family. Thanks to founds: State Assignment, Main Botanical Garden, Russian Academy of Sciences, №18-118021490111-5, Unique Scientific Equipment 'Found Greenhouse'.