Historische Abbildung von Potamogeton praelongus (Langblaettriges Laichkraut - Long-stalked Pondweed). Das Bild zeigt Blatt, Bluete, Frucht und Same. ---- Historical Drawing of Potamogeton praelongus (Langblaettriges Laichkraut - Long-stalked Pondweed).The image is showing leaf, flower, fruit and seed.