Trapa natansin the British Flandrian

POLLEN of Trapa natansL. the water chestnut, has been found in two Flandrian (Holocene) deposits at Skipsea, North Humberside, providing the first in situFlandrian records of this species in Britain. The occurrence, followed by the extinction, of T. natansin Scandinavia has been regarded as evidence of a ‘climatic optimum’ when summer temperatures were at least 2 °C higher than at the present day1–4. The new British data may indicate similar conditions but could also record human activity, in which case it would not be necessary to invoke climatic change.