A literature survey revealed that the semi-parasitic evergreen shrub Viscum album subsp. album (Viscaceae) has been recorded on 53 taxa of deciduous trees and shrubs (including five hybrids) in the Czech Republic,. Of the host taxa, 26 are native and 27 alien to the Czech flora. The range of hosts covers 13 families. Salicaceae (11 taxa), Rosaceae (11) and Aceraceae (7) are most represented among families. Of the 22 genera harbouring mistletoe, Populus (7 taxa), Acer (7), Tilia (5) and Fraxinus (4) are most represented. A locality at the castle park in the town of Heřmanův Městec, E Bohemia, is reported in detail. In 1978–1981 and 2001, Viscum album subsp. album was observed on 15 host taxa of trees and shrubs, which represents the second highest diversity of host trees in a single locality in the Czech Republic; the richest one, previously reported by Unar et al. (1985) is the Lednice castle park, S Moravia, with 24 taxa. Four more host taxa were recorded in the studied town of Heřmanův Městec outside the park, giving the total of 19 hosts concentrated within a limited area. The occurrence of mistletoe on Prunus padus is reported for the first time from the Czech Republic.
The nonlinear difference equation (E) xn+1 − xn = anϕn(xσ(n) ) + bn, where (an), (bn) are real sequences, ϕn : −→ , (σ(n)) is a sequence of integers and lim n−→∞ σ(n) = ∞, is investigated. Sufficient conditions for the existence of solutions of this equation asymptotically equivalent to the solutions of the equation yn+1 − yn = bn are given. Sufficient conditions under which for every real constant there exists a solution of equation (E) convergent to this constant are also obtained.