In the anthers of flowering plants, gymnosperms, and seed ferns, tiny (¡1 mm) granules might occur on the radial and innermost tangential wall of secretory tapetum cells. These sporopollenin granules develop simultaneously with the pollen exine and are called orbicules or Ubisch bodies. The present paper focuses on two quite different topics associated with orbicules. The morphological and ultr...

The two diaporthalean fungi Anisogramma virgultorum and A. anomala are biotrophic parasites. A. virgultorum causes stromatal cankers on young shoots of birch whereas A. anomala infects young branches of Corylus avellana. Although previous classifications based on morphological characteristics placed both species in the Gnomoniaceae, Diaporthales, their taxonomic position within the order and th...

The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest-...

BACKGROUND AND AIMS In some dicotyledonous leaves and leaflets, the secondary veins run more-or-less straight to the margins and have well-defined lengths. For a given half-lamina of length L, an equation, previously proposed, relates the lengths of these veins, p, to the distances, l, between the leaf tip and their insertions on the midrib: p = B2(x+y)l(x)(L - l)(y)/L(x+y-1), where B, x and y ...

Preliminary data from newly excavated archaeological site no. 8 in Kraków-Górka Narodowa (southern Poland) show that two main phases of Early Neolithic occupation can be distinguished based on pottery finds, one associated with the Malice culture and other Pleszów- Modlnica group Lengyel culture. These are presented along lithic materials discussed context results archaeobotanical analysis. Cha...