List of the Flowering Plants [from the Arctic Bed

Abstract

These plants occurred in a layer of peaty sand. Small stems and twigs were not uncommon, and all belonged to the genera Betula and Salix . In most cases these stems were decorticated, and bore evidence of drifting. Most of the seeds and fruits in the list were quite uninjured, but the character of the layer and the assemblage of plants indicate that they were drifted by water to the place where they are now found. Several small pieces of charcoal 5 to 10 mm. square were also found in the general collection, but the carbonization may possibly be due to causes other than fire. A considerable portion of the material consisted of the leaves of Salix herbacea , felted together in lenticular masses. In addition to the plants enumerated in the above list, the washings contained many small petal-like objects. These have not been identified, but they are certainly not the petals of Dryas, Rubus chamœ morus , or Parnassia palustris . Several small brownish flakes were present: these consisted of much-compressed fragments of epidermis and other plant-débris, felted together. The appearance of this material rather suggest the dung of some big mammal. The presence of these plants at sea-level in the Lea Valley indicates a decided difference in climatic conditions from those of the present day. At no place in the world do such plants as Salix herbacea, Betula nana , and Potentilla sibbaldi grow in quantity at sea-level along the annual isotherm of 10° C. or the July isotherm of 17° C.