I walked a section of the South Downs Way one day last week beginning at Eastbourne, over Beachy Head and the Seven Sisters, inland along the Cuckmere Valley then back up on the Downs across to Glynde (about 20 miles in total).
 I treated it as a bit of a route march because I want to get my legs going ahead of another hiking trip in the States in July. I intend to use a stretch of the Pacific Crest Trail to traverse the Castle Crags National Park and Wilderness Area in northern California. The South Downs Way has some of the steepest gradients I could think within an hour's train ride of London. Though I won't be able to purchase a choc ice and a pint of beer on the PCT.

 Needless to say I kept an eye out for the local flora and fauna. I've often noticed that a particular plant will characterize a particular walk at a particular time of year. In this case it was the lovely Viper's-bugloss (Echium vulgare) which favours chalk grassland and sandy coastal habitats. Numerous studies have named it as one of the best bee plants.
 By the by I have seen it growing in some quantity along a gravelly stretch of the London Overground between Shoreditch and Dalston. As I recall the line was seeded with wildflowers when it opened in 2010. Most have failed to establish themselves but Viper's-bugloss and the inevitable Ox-eye Daisies seem to have naturalized.
 E. vulgare and Wild Mignonette (Resedaceae lutea) and of course Ox-eye Daises are the most showy plants along this clifftop walk (all growing together in the last photo of the sequence above) but much of the action is at ground level. Chalk grasslands have only a thin scraping of soil on top of all that chalk but conversely this spartan ground produces a very rich tapestry of low growing wildflowers.
 I'll write more about this in the near future because flowering grasslands like the South Downs are one of our most notable yet most diminished landscapes...