Trimeriantha monopolyada X.-T.Wu, Balthazar, Grímsson, S.Ulrich, López Martínez, Heřmanová, J.Kvaček et Schönenb.

Plant Fossil Names Registry Number: PFN003490

Act LSID: urn:lsid:plantfossilnames.org:act:3490

Authors: X. Wu, M. von Balthazar, F. Grímsson, S. Ulrich, A. López Martínez, Z. Heřmanová, J. Kvaček & J. Schönenberger

Rank: species

Genus: Trimeriantha X.-T.Wu, Balthazar, Grímsson, S.Ulrich, López Martínez, Heřmanová, J.Kvaček et Schönenb.

Reference for this name: Wu, X., von Balthazar, M., Grímsson, F., Ulrich, S., López Martínez, A., Heřmanová, Z., Kvaček, J. & Schönenberger, J. (2026): Trimerous flowers with a unique set of flower and pollen traits from the Late Cretaceous of Southern Bohemia (Czech Republic). – New Phytologist 251(4): 2266–2283.

Page of description: 2269

Illustrations or figures: Figs 1–9

Types

Original diagnosis/description

As for the genus with the following additions. Tepals triangular with a glabrous abaxial surface featuring irregularly shaped epidermal cells and interspersed with few stomata, and an adaxial epidermis that is densely papillate in the middle section, transitioning to flat epidermal cells toward the tip and the base. Basifixed anthers slightly longer than filaments; anthers distinctly bilobed. Pollen sacs of a theca well separated from each other, hemispheric in shape and protruding from the thecal tissue. Each pollen sac opening with a flap-like valve, characterized by papillate epidermal cells. Polyads covered by a continuous-compact exine layer. Individual pollen grains inaperturate and heteropolar, with regulate to fossulate and perforate exine sculpture. Dorsal carpel surfaces and styles densely covered by glandular papillae.

Etymology

The species name monopolyada refers to the presence of a single pollen polyad per pollen sac.

Stratigraphy

Cretaceous, Upper Cretaceous
Klikov Formation, upper Turonian-lower Santonian, Late Cretaceous

Locality

Czech Republic
high way road cut Dobrovodská, street between Dobrá Voda and České Budějovice