water-persicaria

Every bud of the water-persicaria may develop either into an erect or into a floating stem, according as it is surrounded by water or by relatively dry soil.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

The external conditions decide which of them becomes active and which remains inactive, and the case seems to be exactly parallel to that of the water-persicaria.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

The most curious and most suggestive instance of such an alternation is the case of the water-persicaria or _Polygonum amphibium_.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

The two forms of the water-persicaria must remain varieties, though they are only types of the different branches of a single plant.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

Among all the previously described cases of horticultural plants and monstrosities there is no clearer case of an ever-sporting variety than this one of the water-persicaria.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

It is obvious that from the flowers of the floating and erect stems of the water-persicaria seeds will result, each capable of yielding both forms.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

Manifestly this classification is as nearly right as that of the two varieties of the water-persicaria.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

Polygonum amphibium (water-persicaria), var. aquaticum, Second Lake.

The Maine Woods 1858