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The complete sample of large-perihelion nearly-parabolic comets discoveredduring the period 1901-2010 is studied starting from their orbit determination.Next, an orbital evolution that includes three perihelion passages(previous-observed-next) is investigated where a full model of Galacticperturbations and perturbations from passing stars have been incorporated. Weshow that the distribution of planetary perturbations suffered by actuallarge-perihelion comets during their passage through the Solar system has adeep, unexpected minimum around zero which indicates a lack of "almostunperturbed" comets. By a series of simulations we show that this deep well ismoderately resistant to some diffusion of orbital elements of analysed comets.It seems reasonable to state that the observed stream of these large-perihelioncomets experienced a series of specific planetary configurations when passingthrough the planetary zone. An analysis of the past dynamics of these cometsclearly shows that dynamically new comets may appear only when their originalsemimajor axes are greater than 20 000 au. However, only for semimajor axeslonger than 40 000 au dynamically old comets are completely not present. Wedemonstrated that the observed $1/a_{\rm ori}$ distribution exhibits a localminimum separating dynamically new from dynamically old comets. Long-termdynamical studies reveal a large variety of orbital behaviour. Severalinteresting examples of action of passing stars are also described, inparticular the impact of Gliese 710 which will pass close to the Sun in thefuture. However, none of the obtained stellar perturbations is sufficient tochange the dynamical status of analysed comets.

Oort spike comets with large perihelion distances