Rugonella E.M.Friis, K.R.Pedersen et P.R.Crane
Plant Fossil Names Registry Number: PFN002854
Act LSID: urn:lsid:plantfossilnames.org:act:2854
Reference: Friis, E. M., Pedersen, K. R. & Crane, P. R. (2009): Early Cretaceous mesofossils from Portugal and eastern North America related to the Bennettitales-Erdtmanithecales-Gnetales group. – American Journal of Botany 96(1): 252–283.
Page of description: 263
Rugonella trigonospermum E.M.Friis, K.R.Pedersen et P.R.Crane
Seeds small, bilaterally symmetrical (with a single axis of symmetry) and two lateral wings; nearly circular in longitudinal outline in the broadest view, micropylar region slightly pointed; shallowly triangular, three-lobed in cross section with three grooves separating the lobes. Integument thin, micropylar tube long, narrow. Integument enclosed by a seed envelope, except for the micropylar opening, attached to the envelope only at the base. Micropyle open at the apex. Below, micropylar closure distinct, multicellular, with enlarged cells that extends toward the center of the micropyle fi lling the lower half of micropylar tube. Inner surface of seed envelope smooth, nonpapillate; outer surface deeply rugulate, except on the wings. Seed envelope with an inner and an outer layer of sclerenchyma. Cells of inner sclerenchyma layer long, narrow and thin-walled, arching in a distinct chevron pattern. Fiber arches broad and high. Cells of outer sclerenchyma layer longitudinally aligned, narrow. Demarcation between inner and outer sclerenchyma layers distinct.
From the strongly rugulate surface ornamentation of the seed envelope.