Endressistemon sp. 2

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 : 383

cf. Endressistemon sp. 2

Text-fig. 29c, d

Description and remarks. The material comprises a single stamen fragment, about 0.8 mm long including the apical projection, and about 0.3 mm broad. The apical projection is compressed covering the distal portions of the thecae ( Text-fig. 29c ).

Pollen grains in situ are poorly exposed and the aperture configuration is uncertain, although it is clear that the grains are not tricolpate and we assume that the pollen is monoaperturate. Pollen is semitectate-reticulate, circular in equatorial view, about 9 µm in diameter. The reticulum is homobrochate and only loosely attached to the main body of the pollen ( Text-fig. 29d ).

Affinity and other occurrences. The stamen fragment is closely similar in general morphology to the individual stamens of Endressistemon cateficensis , but slightly larger and the reticulum of the pollen grains is more open and only loosely attached to the main body of the grains.

Figures

Text-fig. 29. Scanning electron microscope (SEM) images of stamens and pollen grains of cf. Endressistemon sp. 1 (a, b), cf. Endressistemon sp. 2 (c, d) and cf. Endressistemon sp. 3 (e–g); Catefica locality, Portugal. a) Two adhering stamens, each with a long, pointed extension of the connective; b) Monocolpate, reticulate pollen in situ in stamen from stamen pair in (a); c) Fragment of stamen with prominent apical extension of the connective; d) Reticulate, apparently monocolpate, pollen in situ in stamen fragment in (c); e) Stamen with basifixed anther, perhaps sessile, and with prominent, wing-like apical extensions of the connective; note the dehisced thecae with the anther wall curved back; f, g) Monocolpate, reticulate pollen in situ in stamen in (e). Specimens, Catefica 49-S107780 (a, b), Catefica 49-S107784 (c, d), Catefica 49-S107781 (e–g). Scale bars = 600 Μm (a, c, e), 6 Μm (b, d, f, g).