Horlăceni Ariniș is a reservation spreading over an area of 5 hectares, which accommodates and protects by law the black alder (Alnus glutinosa) or common alder, a deciduous shrub with a dark leaves during the autumn.
The reservation spans on the Jijiei Plain, located in Horlăceni village, Șendriceni commune, and is part of the Forest Division of Dorohoi. It is a reserve forest included in category 4 – ICUN, a management area for the existing habitat.