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

Plant Fossil Names Registry Number: PFN000846

Act LSID: urn:lsid:plantfossilnames.org:act:846

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

Rank: genus

Reference: Friis, E. M., Pedersen, K. R. & Crane, P. R. (2013): New diversity among chlamydospermous seeds from the Early Cretaceous of Portugal and North America. – International Journal of Plant Sciences 174(3): 530–558.

Page of description: 540

Type

Original diagnosis/description

Seeds small and orthotropous. Nucellus fused to integument for approximately one-third to half its length, free apically. Integument free from seed envelope for its full length except at the base where it is broadly attached. Integument apically extended into a long micropylar tube extending beyond seed envelope. Micropylar tube lined by an outer and inner epidermis. Micropylar canal open apically and closed farther down by cells of the inner epidermis that expand radially toward the center of the canal. Seed envelope ellipsoidal in lateral view, distinctly four angled in transverse section except at the base where it is circular to elliptical. Surface of seed envelope shows irregular transverse ridges forming a prominent rugulate pattern. Seed envelope extended in the micropylar region into a short, collar-like central projection supporting the micropylar tube and also into four lateral, narrow, and slightly recurved projections. Micropylar tube interlocked with seed envelope proximally by small pits in its outer surface that correspond to oblique, upwardly turned papillae on seed envelope. Inner epidermis of seed envelope of polygonal cells with thin cell walls. Outer epidermis of seed envelope of narrow, longitudinally elongated cells with a thick cuticle. Seed envelope with an inner sclerenchyma zone and an outer zone of nonlignified cells. Sclerenchyma zone with an inner layer of narrow, transversely elongated cells and an outer layer of shorter, longitudinally elongated cells. Apically, inner sclerenchyma cells enlarged and extend radially. Outer zone with narrow, longitudinally elongated tubular cells, most pronounced near base and apex and over the four longitudinal angles of seed envelope. Tubular cells also extend into the four apical projections.

Etymology

From the apical spines (Greek: acanthos) and catia to indicate resemblance to Tomcatia and Cattomia.