Schimper used the term xerophytes to include plants which live in soils which are physiologically dry, and the term hygrophytes those which live in soils which are physiologically wet or damp. Schimper recognized that the two classes are connected by transitional forms, and that it is useless to attempt to give the matter a statistical basis.
Hygrophytes.Plants which are sub-evergreen or evergreen but it scierophyllous, and which live in moist soils; e.g., Lastraea lix-mas, Poa pratensis, Carex ovalis, Plantago lanceolala, and ihillaea Millefolium.
Hygrophytes.Living, as these plants do, under medium conditions as regards soil, moisture and climate, they exhibit no characters which are markedly xerophytic or hydrophytic. Hence, such plants are frequently termed mesophytes.
An interesting special case of hygrophytes is seen with regard to plants which live in the shade of forests.
Thus all existing hygrophytes (excepting the Algae) are considered to have been derived from land-plants which have adapted themselves to a watery habitat.