Boraginaceae botany Cynoglossum officinale downland England english field flowers Great Britain green Hound's tongue meadow natural nature South Downs summer Sussex wild barley boundary crop edge farm harvest hedge landscape margin rural wiltshire alpine canada coast conifers flora flower flower-head mountains seed seedhead slope stalk sub-alpine trees view Whistler cloud dusk evening glorious glory light rays shafts silhouette sky sun sunset countryside grass hill pastoral ridge wayside clematis climber cream Old Man's Beard plant traveller's joy white campion coastline island maritima Pembrokeshire sea Silene uniflora Skomer spring united kingdom wales water welsh background Brassica napus canola fields national park plants rapeseed seedheads bank bluebell Endymion non-scriptum lane peace Stellaria stitchwort verge