Juglans Juglans Walnut trees are any species of tree in the plant genus Juglans, the type genus of the family Juglandaceae, the seeds of which are referred to as walnuts. All species are deciduous trees, tall, with pinnate leaves , with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts ("Pterocarya"), but not the hickories ("Carya") in the same family. The 21 species in the genus range across the north temperate Old World from southeast Europe east to Japan, and more widely in the New World from southeast Canada west to California and south to Argentina. The
Two-sided market to invest more in R&D or lower their prices, driving out weaker rivals. As a result, mature two-sided network industries are usually dominated by a handful of large platforms, as is the case in the credit card industry. In extreme situations, such as PC operating systems, a single company emerges as the winner, taking almost all of the market. Platform managers must choose the right price to charge each group in a two-sided network and ignoring network effects can lead to mistakes. In "figure 2", pricing without taking network effects into account means finding prices that maximize the areas of