Cuticles and spores of Senftenbergia plumosa (Artis) Bek and Pšenička from the Carboniferous of Pilsen Basin, Bohemian Massif

Abstract

Senftenbergia plumosa (Artis) Bek and Pšenička is an abundant Carboniferous fern occurring in the Central and Western Bohemian Carboniferous basins of the Czech Republic. Its epidermal structures are described in detail for the first time. The abaxial cuticles are very thin. The cells are isodiametric, random, pentagonal or hexagonal in shape. Stomata occur only on the abaxial side of the pinnules. They are irregularly scattered and more or less oriented in one direction; ca. 200 per mm 2, of the actinocytic or cyclocytic, flush with the epidermal cells. The abaxial and adaxial surfaces contain small trichome bases. Sporangia are of the Senftenbergia type with Raistrickia type spores. These are different from those of the previously described fertile specimens of S. plumosa from Bohemia, suggesting a large morphological variability of spores in this species. The epidermal structures of S. plumosa are important for understanding the systematic position of this Carboniferous fern. Generally, the cuticle of S. plumosa is more similar (especially its irregularly, polygonal cells with straight anticlinal wall and cyclocytic stomata) to that of living species of Marattiaceae than of Schizaeaceae. The epidermal cells of S. plumosa are very similar to those of the Tedelea glabra. It appears to confirm that S. plumosa is a member of the primitive Carboniferous fern family Tedeleaceae (Jennings and Eggert, 1977; Taylor and Taylor, 1993; Bek and Pšenička, 2001).