Character Coding and Rationale

Fruit morphological characters and life form were scored (Supplementary Table S3). Life form was coded as terrestrial (0) or epiphytic (1), with geophytic and lithophytic considered as terrestrial (Zotz, 2013). We scored the general presence of fruit’s adhesiveness (manually tested) as absent (0) and present (1). It is, however, unclear if the fruit stickiness originates from anatomically homologs structures. Fruit adhesiveness is caused by epidermal structures, which may be secretive papillate cells (Peperomia subgenera Micropiper, Oxyrhynchum, Leptorhynchum), or the so-called pseudocupula (Peperomia subg. Pseudocupula). The latter was reported as an epidermal structure covering the fruit base (Dahlstedt, 1900). In addition, punctual sticky secretion is observed as an intermediate state in some species of Peperomia subg. Oxyrhynchum. In those cases, stickiness could be verified, but the secreting structures were neither pseudocupula nor papillate cells. Fruit trichomes of P. hispidula and P. hispiduliformis were not regarded as adhesive because they are not glandular (Martínez-Colín et al., 2006). The pseudopedicel represents a stalk-like outgrowth of the rachis and has been regarded as a dispersal-related structure that develops during fruit maturation (Dahlstedt, 1900; Yuncker, 1958). It was coded as absent (0) or present (1). The fruit apex is potentially relevant for dispersal as it forms hook-shaped appendages in some species and was coded as being absent (0) or present (1).

For the analyses of fruit character evolution we pruned outgroup species, as character states were not applicable. Drupes of the genus Piper differ notably in size, color and amount of fleshy mesocarp and show no obvious structures for mechanical attachment and external dispersal (Yuncker, 1958) (Rauh, 1950). The analysis of life form is based on 1520 Peperomia species and additionally includes outgroup lineages (Isnard et al., 2012).