It looks like you've picked up a duplication error in our descriptions - thanks for spotting it and we'll get it corrected. An easy way to tell them apart is that Sun Spurge has toothed leaves (the only UK spurge to have these) and Petty Spurge leaves are untoothed. In practice they are easy to tell apart without looking too hard. Sun Spurge is larger and has saucer shaped (sun-shaped?) flowers. It also tends to be more yellowy green, particularly when young. Petty Spurge is more spindly and has less showy flowers.
Hi Peter,
It looks like you've picked up a duplication error in our descriptions - thanks for spotting it and we'll get it corrected. An easy way to tell them apart is that Sun Spurge has toothed leaves (the only UK spurge to have these) and Petty Spurge leaves are untoothed. In practice they are easy to tell apart without looking too hard. Sun Spurge is larger and has saucer shaped (sun-shaped?) flowers. It also tends to be more yellowy green, particularly when young. Petty Spurge is more spindly and has less showy flowers.
Dave