The moist soil encourages luxuriant thickets of willows (Salicineae), surrounded by dense chevaux-de-frise of wormwood and thornbearing Compositae, and interspersed with rich but not extensive prairies, harbouring a great variety of herbaceous plants; while in the deltas of the Black Sea rivers impenetrable beds of reeds (Arundo phragmites) shelter a forest fauna.
Amoena, amoena spectabilis, magnifica, paronychioides major aurea and amabilis; Alyssum maritimum variegatum; some of the dwarf varieties of Antirrhinum majus; Arundo Donax variegata; Begonias; Calceolarias; Cannas; Centaurea ragusina; Clematises, of which the hybrids of the Jackmanni type are best; Dahlia variabilis, and the single-flowered forms of D.
The tendency of the dunes to drift off on the landward side is prevented by the planting of bent-grass (Arundo arenaria), whose long roots serve to bind the sand together.
The most common plant here is the stiff sand-reed (Arundo arenaria), called sand-oats in Drente and Overysel, where it is much used for making mats.
Less favourable signs are furnished by such plants as Arundo Donax (in Germany), Cicuta virosa and Typha latifolia, which are found in stagnant and torpid waters.