Lomariopsis

Kvaček, Zlatko & Teodoridis, Vasilis, 2011, The Late Eocene Flora Of Kučlín Near Bílina In North Bohemia Revisited, Acta Musei Nationalis Pragae Series B 67 (3 - 4), pp. 83-144 : 87

Lomariopsis (?) bilinica ETTINGSHAUSEN

Pl. 1, figs 7-8

1866 Lomariopsis bilinica ETTINGSHAUSEN , p. 13, pl. 3, fig. 13. 2001 Blechnum dentatum (GÖPP.) HEER ; Hably in Hably et al.,

p. 27, pl. 20, fig. 1.

Fragmentary sterile pinna (or complete frond?) ribbonshaped, parallel-sided, exceeding 100 mm in length, max. 20 mm in width, margin sub-entire, with rare widely spaced widely triangular sharp teeth corresponding to single craspedodromous secondaries, midrib straight, medium thickened, secondaries straight, simple, or occasionally simple forked at base or exceptionally higher, max. in half the distance to the margin, at an angle of 70–80°, in 1–1.5 mm spacing, either gently joining the margin or straight entering the teeth.

Because of its larger width, Ettingshausen (1866) compared this single fern fragment from Kučlín with acrostichoid ferns of the genus Lomariopsis FÉE ( Lomariopsidaceae ). Hably (in Hably et al. 2001, p. 27) transferred this record into the synonymy of Blechnum dentatum ( Blechnaceae ). Indeed, larger pinnae of Blechnum dentatum (see, e.g., Kvaček and Hably 1991, pl. 2, fig. 3) are superficially similar to the Kučlín specimen. However, its pinnae are regularly crenulate and the secondaries mostly twice forked. The pantropical genus Lomariopsis recalls more the fossil fragment but has a typical heterophylly. Fertile pinnae show acrostichoid sori and sterile foliage is more variable in its morphology, mostly entire-margined or densely finely toothed ( Holttum 1978, Moran 2000). By the irregularly toothed margins Cyclopeltis jani Barthel (1976) from the Upper Eocene of the Geiseltal matches superficially the Kučlín sterile pinna. Its systematic affinity is corroborated by the position of sori and character of spores in situ ( Barthel 1976, p. 464, pl. 85, 86, figs 9a-d, text-figs 8 a-b). Although it shows a very similar venation and marginal morphology, its pinnae are much narrower (8 mm). A similar sterile pinna from the Middle Eocene of Eckfeld ( Frankenhäuser and Wilde 1993) differs still more in denser and more dichotomizing secondaries. After consulting pteridological monographs and herbarium specimens it becomes clear that such fragments of sterile fern foliage with free secondary veins are hardly determinable to a genus ( Barthel 1976, Frankenhäuser and Wilde 1993).

M a t e r i a l: BP 55.2489.1

Blechnaceae