Studies in Plant Transpiration. II.

In a previous paper (B) a torsion balance method for transpiration measurements in excised leaves or shootshas been described, and values obtained in experiments with Vaccinium myrtillus cited. In the present paper the results of further measurements by the same method are reported. Two more species of Vaccinium have been fairly well investigated, viz.. V. uliginosum and V. vitis-idaea. Besides, less extensive series of experiments have been made with samples of the following species: Alchemilla alpina, A. glabru, A. glomerulans,, Antennaria dioica, Calluna vulgaris, Empetrum hermaphroditum, Mianthemum bifoiumi, Pingucicula vulgaris,. Potentilla palustris. Rubuns Chamaemorus, Salix herbacea, Saussurea alpina, Saxifraga aizoides, Sibbaldia procumbens, and Viola palustris. In many cases samples of the same species were taken from several ecologically distinct localities. The course of the transpiration decline curves obtained in these experiments is described elsewhere (7). In the present paper the transpiration values calculated from the curves are reported and their significance discussed. [ABSTRACT FROM AUTHOR]