Lotus corniculatus, Bird's-Foot Trefoil, is a UK native herbaceous perennial more commonly associated with wildflower meadows, roadside verges or cottage gardening than exotic gardening yet it creates an ideal and very colourful ground-cover during the summer as it creeps and scrambles across your carefully designed jungle-floor and looks so much better than bare soil or the stark brown blandness of most mulches as it quietly fixes nitrogen into the substrate. The combination of attractive pinnate foliage, pollinator-friendly flowers and roots with nitrogen-fixing nodules is a winner.