Original paper

The family Myodocarpaceae: looking at the system from the standpoint of comparative carpology

Konstantinova, Alexandra I.; Yembaturova, Elena Yu.

Abstract

The fruit structure of five Myodocarpus species and four Delarbrea species (Myodocarpaceae, Apiales) was studied. It was found that the species studied share several fruit structure traits, such as: dimerous gynoecium, presence of peculiar secretory cavities (“oil vesicles”) and a free column separating from mericarp tissues. However, many distinctions in fruit structure of Myodocarpus and Delarbrea were also revealed: pericarp consistence (dry versus fleshy), dispersal type (anemochory versus zoochory) and details of column separation mode, presence or absence of sclereids, groups of “hydrocyte parenchyma” cells and tannins in the pericarp as well as secretory canals location pattern. Myodocarpus and Delarbrea also show some differences in the seed coat structure. Data from comparative carpology confirm that Myodocarpaceae comprises modern remnants of an ancient branch of Apiales evolutionary tree. Myodocarpus and Delarbrea, closely related to Araliaceae and Apiaceae, share some features of both families, although they are obviously distinct. Within Myodocarpaceae, Myodocarpus and Delarbrea represent different phylogenetic lineages and their fruit structure provides evidence for that. Moreover, carpological data strongly support the presence of two groups within Myodocarpus.

Keywords

delarbreamyodocarpusanatomy and morphologyfruit structuredispersal patternphylogenetic lineages