I have recently returned from a visit to the David Hockney exhibition in the Royal Academy, and what a delight it was – a huge celebration of the amazing greenness of Yorkshire in spring and summer. Our native plants are well worth celebrating, and much of the glory of our countryside is tied up with them. Indeed, returning from far distant countries, one never fails to be astonished by the greenness of Britain and Ireland, revelling as they do in a temperate Atlantic climate which allows a long season of plant growth as well as the survival of many winter evergreens.

Our native flora consists of about 1300 vascular plant species (about which I strongly recommend Richard Mabey’s Flora Britannica), most having colonised from southern Europe following the retreat of the ice some 10 000 years ago. During the last glaciation Britain lacked both oak and beech woods, and grassland existed only in the south. Oliver Rackham’s book on Woodlands is an excellent reference book on this topic. Later, Neolithic agriculture, which thrived some 6000 years ago, brought crops and domesticated animals, and the woods that had sprung up after the glaciation were frequently felled for firewood and hut construction, or cleared for pastoral agriculture. The widespread agriculture that has characterised our islands since about 1500 has brought with it new opportunities for arable weeds and the spread of plants characteristic of hay meadows. Coppiced woodland also encouraged plants which grew well in dappled shade, such as hellebores and herb paris (Paris quadrifolia). The planting of hedges has also been a crucial factor, helping the spread of small trees within the hedges such as blackthorn (Prunus spinosa), spindle (Eunonymus europaeus), cherry (Prunus avium) and hawthorn (two species: Crataegus monogyna and Crataegus oxyacanthoides). So evolved what we have come to think of as the characteristic countryside of our islands.