Proencistemon sp.

Friis, Else Marie, Crane, Peter R., Pedersen, Kaj Raunsgaard, Mendes, Mário Miguel & Kvaček, Jiří, 2022, The Early Cretaceous Mesofossil Flora Of Catefica, Portugal: Angiosperms, Fossil Imprint 78 (2), pp. 341-424 : 357

Proencistemon sp.

Text-fig. 9h–j

D e s c r i p t i o n a n d r e m a r k s. The material includes a single staminate inflorescence fragment consisting of about seven tightly packed, stamens that lack a well-developed filament and have anthers that are almost sessile ( Text-fig. 9h). Anthers are elongate, narrowly obtriangular, and 0.45 mm broad. Their full length is not preserved, but they are more than 0.8 mm long. Pollen grains are trichotomocolpate, about 16 µm in diameter, and semitectate-reticulate ( Text-fig. 9i, j). These grains are very similar to pollen found in situ in the stamens of Proencistemon portugallicus .

A f f i n i t y a n d o t h e r o c c u r r e n c e s. Pollen grains of Proencistemon sp. are closely similar in size, shape, aperture configuration and details of pollen wall to those found in situ in Proencistemon portugallicus , but the anthers are longer and differ in their narrow obtriangular shape. More material is needed to determine if a new species should be recognized formally. We have not observed similar stamens and pollen in other Early Cretaceous mesofossil floras from Portugal.