The trouble with doing things alphabetically is that you inevitably get to a letter that poses problems! I have no worries about those ‘tricky letters’ at the dumpster end of the alphabet – those are ready to roll – but Q? So quadrifolium is a bit of a ‘cop out’, meaning four leaves. And the example has to be good old Paris quadrifolium with its four leaves in a whorl just below that curious flower with four petals.
‘Four-leaved’ plants are not that common and leaves tend to be divided into three, five or more leaflets. The famous exception is the fabled four-leaved clover which is supposed to bring good luck to the finder, because of its rarity. Usually just one or two leaves appear on a plant of Trifolium repens, the common white clover, and I have spent many childhood moments looking for them. If you don’t have the time to waste (though it is a useful activity at picnics) you could plant Trifolium repens ‘Purpurascens Quadrifolium’ which is a cultivated form that has a large proportion of leaves with four leaflets and sometimes even five. It is a nice ground cover with purple-tinted leaves though it must have identity problems with a name that means ‘three leaves, creeping, purple, four leaves’!