Water Caltrop

The Water Caltrop (Trapa natans) is the only representative of the genus Trapa and the family Trapaceae in R.N. Macedonia (monocotyledons, Liliopsida). It is an annual aquatic herbaceous plant with an unbranched stem, 20 ÷ 200 [cm] long. The underwater leaves are finely cut or in the form of threads, while the leaves that float on the surface of the water (floating leaves) are rhombic in shape, with serrated edges, gathered in a rosette and with long leaf stalks that are swollen in the middle. Individual whitish or yellowish-whitish flowers develop in the armpits of the short, thick stalk covered with hairs. The fruit is a stalk with 4 retained horny growths, in which 1 to 2 seeds are formed. The Water Caltrop is found in stagnant waters, swamps and lakes in much of Europe and Asia. In other parts of the world it is considered an introduced and invasive species. Although this species is widespread in Europe, its population is declining, mostly due to the drying up of wetlands. For this reason, in Europe this plant is protected by the Bern Convention. In R.N. Macedonia, this was registered in Dojran and Prespa Lakes, Bitola - along Crna Reka, near the village of Skocivir, Monospitovsko and Katlanovsko Blato. In NP Ezerani Trapa natans is found in the community of water millennium and white water lily (Myriophyllo-Nupharetum). This community was previously registered on the shores of Lake Prespa, below the village of Dolno Perovo. The Water Caltrop is listed in Annex I of the Bern Convention.