Simple leaves, 19th-century artwork. Simple leaves are those where the leaf either forms a single blade, or is divided into lobes as opposed to the separate leaflets of compound leaves (see C015/6084). Artwork from 'Encyclopaedia Metropolitana', an encyclopedia published in London between 1817 and 1845. Thirty volumes were issued in 59 parts, with 22,426 pages and 565 plates. This plate is dated 1826.