The largest amber-preserved flower revisited

Abstract

Amber exquisitely preserves the delicate organs of fossil flowers for millions of years. However, flower inclusions can be rare and usually do not exceed 10 mm in size. Here we report an exceptionally large flower from late Eocene Baltic amber, measuring 28 mm across, which is about three times as large as most floral inclusions. This fossil was described over 150 years ago as Stewartia kowalewskii (Theaceae) and has never been revised. The analysis of pollen extracted from the anthers of the flower inclusion, however, revealed strong affinities to Asian species of Symplocos (Symplocaceae), prompting the new combination Symplocos kowalewskii comb. nov. et emend. This fossil represents the first record of Symplocaceae from Baltic amber and supports affinities of its flora to evergreen broadleaved and mixed mesophytic forests of present-day East and Southeast Asia. The rarity of such large-sized flower inclusions is likely due to the size of the resin outpouring and its properties, which might affect the embedding of plant organs.

Stop and go signals at the stigma–pollen interface of the Brassicaceae

“…In many taxa, especially in insect-pollinated plants such as crucifers, the exine is highly sculptured and exhibits a species-specific reticulate pattern that might contribute to the species-specificity of pollination ( Edlund et al 2004 ). This pattern may be used for species identification even in 33-million-year-old flowers preserved in amber ( Sadowski and Hofmann 2023 ). Cavities in the exine are filled with a largely tapetum-derived heterogenous viscous, sticky, and semi-solid matrix called pollen coat or tryphine.…”

First Record of the Genus Cartorhynchites Voss, 1958 (Coleoptera: Rhynchitidae) from Eocene Baltic Amber with a List of Fossil Tooth-Nosed Snout Weevils

“…Symplocos kowalewskii (Casp.) Sadowski et Hofmann has recently been reported in Baltic amber [ 75 ]. This extinct plant could be a suitable host plant for Cartorhynchites groehni sp.…”

“…New descriptions of species and genera have significantly added to the picture of the fossil beetle assemblage in the Fennosarmatian landmass during the Late Eocene and made adjustments to the conclusions about the paleoecosystems of amber forests. The recent active work on the inventory of the Baltic amber flora [50,51,75,[130][131][132][133][134][135] provides a very useful tool for understanding the possible trophic habits of phytophagous beetles and for the reconstruction of possible "host plant-phytophagous beetle" associations in the Paleogene. The family Rhynchitidae is a small part of the Eocene Baltic amber assemblage, consisting of 13 species within 8 genera, but the ongoing study of tooth-nosed snout weevils is a promising addition to the understanding of the interactions between plant-feeders and vegetation as well as the late Eocene stage of insect-plant co-evolution.…”