I believe that it's Mediterranean Spurge (Euphorbia characias), and, if I might be so bold, of the ssp veneta. There will, no doubt, be somebody out there ready to correct me if I'm wrong. Nearby in Ewell, close to Bourne Hall, the Creeping Comfrey (below) and Abraham-Isaac-Jacob (next two images) are at their best.
Even though a nagging easterly wind is present today, the butterflies have come out in numbers, particularly Brimstones. Also recorded were Comma (first image), Small Tortoiseshell (next) and Red Admiral.
The birds haven't been neglected - two Red Kites flew through Priest Hill (one north and the other east), a Common Buzzard passed high overhead northbound, and two Chiffchaffs were in full song in the copse area.