Crataegus monogyna oneseed hawthorn Dutch treeguide at www.bomengids.nl, European trees

_{This is the page featuring a single species. Photographs are presented per individual to make it possible to asses how much variation is possible between individuals within the species.}

All photographs of Oneseed hawthorn or Crataegus monogyna and English hawthorn Crataegus laevigata (Rosaceae)

Determining what species your specimen is can be tough because the two look alike. The Oneseed hanthorn has one mostly flowers with one stem (sometimes two) while the English has two and only sometimes one. The same goes for the number of seeds in the red berry-like fruits.
The leafs are also almost identical. However, the Oneseed has leafs with scharp points and most often 5 or 7 lobes, that are devided by deep fissions. The English hawthorn has most leafs with 3 to 5 lobes where the points are more rounded. You should look carefully though because the Englsih hawthorn sometimes also has some or even many 5-7 lobe leafs tha differ not too much: just a bit more rounder edges and less deeply fissioned. It is a god idea to sample more than just a few leafs before you judge what species it is.