Taxonomical software

to diagnosis
of Central European oak species

Introduction to the Central European oak taxa
Although oaks are still the most dominant broadleaved tree species in Central Europe, their taxonomy and genetics are not yet sufficiently known. Oaks can be found under great variety of site condition and tend to form different races. Transitional forms between species are very common too. This is partly because, except for Q. cerris, oaks hybridize among themselves. In addition, variability of important traits, such as early flowering and bud burst, are similarly observable. It is generally recognized that the Central European oak taxa belong to the subgenus Quercus or Lepidobalanus (Q. robur, Q. petraea, Q. pubescens and a few populations of Q. frainetto) and subgenus Cerris (Q. cerris). Within Q. petraea and Q. pubescens further taxonomic subdivision has been advocated by numerous botanists, but is not yet accepted by forestry practice. Accordingly, Q. petraea s. lat. is divided into Q. dalechampii Ten., Q. polycarpa Schur and Q. petraea s. str.; and Q. pubescens s. str. is differentiated from Q. virgiliana Ten..

Pedunculate oak (Q. robur)
The species has been exposed to very instense human effects (seed transfer, artificial regeneration, selection cutting. In Central Europe, first of all in Hungary, pedunculate oak of Slavonian origin has been extensively planted since the end of the last century. Although the Slavonian populations can be easily discerned based on the exceptionally straight stem, relatively regular crown and upward pointing branches, recent genetic investigations do not justify the separation of this provenance from other popultions in Central Europe.

Sessile oak (Q. petraea sensu lato)
Three small species belong to the classical sessile oak aggregate.
-Quercus petraea in a strict sense is an Atlantic species jointly occurring with hornbeam and thriving on cooler mountain slopes with seeping water supply.
-Quercus dalechampii is the species of the southern slopes, often associated with Quercus cerris. This species reaches the northern limit of its distribution in Hungary.
-Quercus polycarpa is also a species of southern type, its ecological features resemble to those of pubescent oak, and it often intermixes and intercrosses with other oaks.

Pubescent oak (Q. pubescens sensu lato)
Pubescent oaks inhabits the extremely dry hill and mountain slopes. These sites have been mostly planted with Austrian pine in the recent decades. Quercus pubescens and the less known Quercus virgiliana are, however very valuable because of their tolerance of arid condition should be therefore preserved and propagated.

How to cite this software:
Borovics, A. 1999. Separability of pedunculate and sessile oak aggregate: a contribution to the hybrid and small species estimation. Erdeszeti Kutatasok 89: 93-110.

If you have any question on numerical taxonomy of oaks, please contact Borovics Attila,
Should you require any further information on JavaScript, please contact Juhász János.