3 (7)m, Large-leafed Dutchman's Pipe (syn. Aristolochia durior) is a quite tall wooden vine with very large oval leaves and yellowish-brown flowers with a reddish-black center followed by long ovoid fruits in autumn. Requires a climbing aid. Easily cultivated in any humus rich, well drained soil in partial shade to full sun. A fully winter hardy species. VII-VIII.