Twig with attached leaves, fruits and seeds of Decodon (Lythraceae) from the Lower Miocene of northern Bohemia, and implications for the identification of detached leaves and seeds

A twig fragment with attached verticillate leaves and capsules with intact seeds was recovered from the Lower Miocene lignitic clay in the Bilina stri p mine (northern Bohemia). The seeds correspond to those known in dispersed condition as Decodon gibbosus (E.M. Reid) E.M. Reid in Nikitin, while the foliage matches that which has been called Ficus multinervis Heer, and some times Apocynophyllum helveticum Heer. While the determination of the seeds is safe, the identity of the isolated foliage may be less secure. Therefore the name Decodon gibbosus is given preference to designate the whole plant . This fossil species differs from the only extant species D. verticillatus (L.) Ell. of eastern North America by narrower triangular shape of seeds i n transverse section, the thicker spongy layer of the testa on the dorsal s ide, and by long petiolate leaves that are more variable in shape (from nar row linear-lanceolate to broadly lanceolate) with more densely spaced secon daries and intersecondaries. The leaf cuticular structure matches that of t he glabrous form of D. verticillatus. The associated plant assemblage sugge sts aquatic to swampy environment typical of the extant relative, (C) 1999 Elsevier Science B.V. All rights reserved.