The paper describes a new taxon: Pyrus × myloslavensis, i.e. a spontaneous hybrid between P. communis (Common Pear) and P. salicifolia (Willowleaf Pear), found near Miłosław town (Wielkopolska province, West Poland). No such hybrid has been reported in the literature so far. P. × myloslavensis has elliptic leaves, 1.1–7.6 cm long and 1.0–2.9 cm wide, margin entire, near the apex shallowly and remotely serrate, shortly acute, silvery tomentose on both sides. Fruit of the hybrid is relatively large (mean weight 56.2 g), green-yellow, without rust-coloured patches and blush.
Interspecific compatibility and self-compatibility in Pyrus communis, P. pyraster and P. salicifolia were evaluated. Degree of compatibility was determined by means of fluorescence microscope. Self-incompatibility evaluated on the basis of the pollen tubes growth showed that two cultivars of P. communis (Bera Hardy and Lukasówka) were self-compatible and the other three cultivars were self-incompatible. All ecotypes of P. pyraster are self-incompatible. In interspecific crosses full inter-incompatibility or unilateral self-incompatibility was observed.