Gastonispermum E.M.Friis, P.R.Crane et K.R.Pedersen
Plant Fossil Names Registry Number: PFN000088
Act LSID: urn:lsid:plantfossilnames.org:act:88
Reference: Friis, E. M., Crane, P. R. & Pedersen, K. R. (2018): Extinct taxa of exotestal seeds close to Austrobaileyales and Nymphaeales from the Early Cretaceous of Portugal. – Fossil Imprint 74(1–2): 135–158.
Page of description: 138
Gastonispermum portugallicum E.M.Friis, P.R.Crane et K.R.Pedersen
Isolated seeds occurring singly. Seeds small, anatropous, bitegmic and exotestal. Seeds bilaterally symmetrical with a dorsiventral plane of symmetry. Seed surface smooth without longitudinal ridges. Raphe distinct, seen externally as a slightly raised rounded ridge that extends from hilum to the chalazal end opposite the micropyle. Hilum and micropyle separated by a narrow zone of sclerenchyma. Hilar scar small, slightly raised without a hilar rim. Micropyle formed by the inner integument (tegmen) and marked on the seed surface by a Y-shaped slit through the outer integument (testa) adjacent to the hilar scar. Testa formed from an outer layer (exotesta) of palisade-shaped sclerenchyma cells and an inner thin layer of thin-walled parenchyma cells (mesotesta/endotesta). Palisade-shaped cells of exotesta with evenly thickened anticlinal walls and a straight lumen. Anticlinal walls of palisade-shaped sclerenchyma strongly undulate toward the inside and toward the outside, resulting in stellateundulate facets and a jigsaw puzzle-like pattern on the seed surface. Tegmen thin. Embryo tiny with two rudimentary cotyledons.
In recognition of Gaston de Saporta (*1823, †1895) for his pioneering contributions to studies of the Mesozoic floras of Portugal.