a salt-tolerant plant that grows on solonchaks and other saline soils. Solonchak plants include many species of various families and range from low-growing annuals to large shrubs and even trees (for example, Haloxylon aphyllum).
Some solonchak plants are capable of normal development (flowering and fruit bearing) only on solonchaks. As a result of high osmotic pressure, enough water to sustain the life processes of the plants and dissolved nutrients from highly concentrated saline solutions enter the tissues of the annual succulent shoots and leaves. In the USSR most of the solonchak plants requiring solonchaks belong to the family Chenopodiaceae (glasswort, Halochenum strobilaceum, saltwort, Russian thistle, Petrosimonia, Halostachys, seablite). A few belong to the families Compositae (sea aster, Saussurea salsa), Caryophyllaceae (sand spurry), Cruciferae (Lepidium crassifolium), Primulaceae (sea milkwort), Plantaginaceae (sea plantain), and Asparagoideae.
Solonchak plants capable of normal development in soils lacking a high salt content are said to be facultative. They usually lack the morphologically pronounced characteristics of solonchak plants requiring solonchaks, but they are adapted to withstand high salt concentrations when necessary. Facultative solonchak plants excrete the excess salts that accumulate in the tissues through special glandules (Aeluropus, statice). Their roots are distributed in the less saline layers of the soil (many grasses, sedges), and osmotic pressure in the tissues is fairly high (wormwood). Facultative solonchak plants include species of many families, including Compositae (Artemisia halodendron, Bhaponticum salinum, Karelinia caspia), Juncaceae (mud rush), Iridaceae (Iris halophila), Polygonaceae (golden dock, Marshall’s dock), Cyperaceae (sea bulrush), Plumbaginaceae (sea lavender), and Gramineae (Aeluropus, alkali grass, Agropyron elongatum, wheatgrass, wild rye).
Succulent solonchak plants are eaten by animals only in autumn and winter, when their salts are leached out by precipitation. All other solonchak plants are consumed through the growing season. Some plants, including alkali grass, Aeluropus elongatum, and Petrosimonia triandra, are good feed crops and can be cultivated on saline soils.
P. A. GENKEL’