The nasturtium (Tropaeolum minor) was first found growing in Mexico and Peru and introduced to England in 1574.
Nasturtiums, as well as being exceptionally cheery flowering plants, have such unusual rounded leaves.
There are old-fashioned spiraeas with lacy white flowers such as ‘Bridal Wreath’ that are quite large, as well as many new dwarf cultivars on the market.
Euphorbia, commonly called spurge, is a succulent and is a valuable plant for use in hot dry sites.