Abstract
For 50 years or more, red clover, hairy vetch and orchard grass have been cultivated in Morioka, and now some of them have escaped abundantly from the fields. The osmotic value of these escaped plants was observed, by measuring the osmotic pressure of the epidermal cells of leaves at incipient plasmolysis in cane sugar solution. On these plants the osmotic value fulactuates daily, the maximum value appears in the noon, and the minimum in the early mornieg. On summer days before flowering, the maximum value is 0.35-0.36 on red clover and hairy vetch, and 0.36-0.37 on orchard grass, since these plants show 0.34-0.35 of osmotic value at 8 a.m., about 94-97% of the maximum value. In winter, the osmotic value of these plants is very high, red clover shows 0.60 value under the snow. The osmotic value also changes according to the growth periods of these plants, it falls gradually from spring to summer, about 0.36 in early summer. But it starts to ascend on some 10 days before flowering. In flowering time it falls suddenly and then ascend again to reach fruiting stage, in this stage the osmotic value is about 0.38-0.39. On the seedlings of these plants cultivated in pots, the osmotic value is 0.33-0.35, after germination, it continues to ascend after germination and reach flowering time, since on red clover and hairy vetch it falls a little before ascending.
