Eat your greens

I love spring greens. Steamed lightly, they are sweet and nutty - I could eat a whole plateful on their own - and full of goodness. I recently discovered sprout tops as a winter treat. I've also read that pea shoots are a trendy accompaniment to salads. Preparing a bargain cauliflower reduced at Sainsbury's the other day it occurred to me that maybe I shouldn't be discarding the leaves for composting. That got me wondering which leaves are edible and which are not! I know for sure that rhubarb leaves are poisonous. They contain high levels of oxalic acid, also worryingly - according to Wikipedia - found in sorrell, star fruit (carambola), black pepper, parsley, poppy seed, amaranth, spinach, chard, beets, cocoa, chocolate, most nuts, most berries, and beans! Yikes! I also assume that the leaves of the potato, which contain solanine, are to be avoided - tho it's rare to hear of anyone dying from eating green bits of spuds. Solanine is also found in (green) tomatoes and aubergines, so I suppose their leaves are out too. So, what other vegetable leaves can we eat - and which taste good? Beetroot, kohl rabi, celeriac, turnip, swede? What about carrot tops, and the leaves of radishes (yes, says Wikipedia)? Or should they just go to compost? Good old Wikipedia says that nearly 1000 species of plants with edible leaves are known, and lists them here, but this doesn't really tell me what I want to know. Recipes please.