Twayblade is older English for two leaves, a typical habit of a number of orchids. They grow from overwintering thickened stems called pseudobulbs. The remains of old ones can often be seen at the base of the new stem. You can see similar structures with the exotics now sold at box stores.
Green twayblade is now extirpated in Norway and Bulgaria. Europe has far fewer species than we do. The barrier created by the Mediteranean Sea limited the number moving north after the last glaciation. Because of that, and population pressures, as many as 25% of species are threatened. The EU has agreed that the 28 member states will protect species and habitats that are at risk. Green twayblade is one of their listed plants.