A sleeping beauty. That is the Calathea 'Elger grass'. The Calathea points its leaves upwards in the evening. The leaves re-open in the morning. Then the pointed shape and glossy green of the leaves can be seen once more.
This jungle plant needs high humidity. That is why we spray the leaves at least once per week. This prevents the leaf edges from drying out. The Calathea likes moderate sunlight, so this plant should not be placed in full sun. Always keep the soil moist, without letting the plant stand in water.