Bicatia E.M.Friis, K.R.Pedersen et P.R.Crane

Plant Fossil Names Registry Number: PFN002866

Act LSID: urn:lsid:plantfossilnames.org:act:2866

Authors: E. M. Friis, K. R. Pedersen & P. R. Crane

Rank: genus

Reference: Friis, E. M., Pedersen, K. R. & Crane, P. R. (2014): Welwitschioid diversity in the Early Cretaceous: evidence from fossil seeds with pollen from Portugal and eastern North America. – Grana 53(online)(3): 175–196.

Page of description: 178

Type

Original diagnosis/description

Seeds small, orthotropous. Integument free from seed envelope for its full length except at the base where the integument is broadly attached to the seed envelope. Integument apically extended into a long micropylar tube. Micropylar tube comprising an inner and outer epidermis. Inner epidermis lining the micropylar tube heavily cutinised. Micropylar canal open both apically and also farther down; without cellular closure. Seed envelope disymmetric, two-winged and flattened, elliptical to obtriangular in dorsi-ventral view, narrowly elliptical in transverse section. One face typically convex, the other convex, flat or concave. A longitudinal midrib may or may not be present on one or both faces. Surface of seed envelope almost smooth, rugulose or rugose with transversely aligned ridges that may branch and anastomose. Seed envelope extended in the micropylar region into a short apical projection that supports the micropylar tube. Papillae absent in the micropylar region. Inner epidermis of seed envelope composed of relatively large, longitudinally elongated polygonal cells with thin cell walls. Outer epidermis of seed envelope composed of longitudinally elongated cells with a thick cuticle and sometimes with prominent circular thickenings. Sclerenchyma zone of seed envelope with several layers of narrow, elongated cells, that are aligned transversely over the main seed body, but aligned longitudinally laterally near the wings and towards the inside of the seed. Parenchyma zone of small equiaxial cells, especially well-developed laterally where this zone between the sclerenchyma and outer epidermis contributes to the formation of the wings. Pollen polyplicate, monocolpate.

Etymology

From the two-sided seed envelope (in Latin combinations: bi- for two-) and ‘-catia’ indicating a broad similarity to other chlamydospermous seeds with a rugulate surface such as Tomcatia, Cattomia and Acanthocatia.