In 2 areas of deciduous woodland, measurements were made of the spatial variation in the shoot biomass and species-composition of the ground flora and of the amount of persistent tree litter. At each site, 4 random 0.0625-m2 samples were collected from the woodland floor in late spring. A negative correlation occurred between total shoot biomass of the ground flora and the amount of tree leaf litter. The largest amount of tree litter occurred in hollows, some of which were devoid of herbaceous vegetation. The weight of tree litter varied between 11 and 636 g per m2 and ground flora species showed marked differences with respect to their pattern of occurrence within this range. In terms of their tendency to occur in areas with large litter accumulation, the main ground flora constituents were arranged in the series Galeobdolon luteum, Endymion non-scriptus, Anemone nemorosa > Milium effusum, Holcus mollis, Poa trivialis > Mnium hornum. This series is related to the relative abilities of the shoots of the species concerned to penetrate layers of persistent tree leaf litter.