A reference data set for estimating phenotypic traits of the three thallose liverworts Riccia glauca, Riccia sorocarpa, and Riccia warnstorfii

The genus Riccia (thallose liverworts, order Marchantiales within the plant kingdom Bryophyta) constitute a diverse and understudied group of non-vascular land plants regarding their biology, ecology and evolution. Species of Riccia are extremely difficult to identify using anatomical and morphological properties as they possess only few discernable phenotypic characters and other properties which often impede ecological and evolutionary studies. Here, we present a bioimaging reference dataset that can be used to aid species identification, allows to estimate phenotypic traits, or to be further connected to molecular data using e.g. eco-metabolomics.