For days together the traveller sees no other vegetation; even this, however, disappears as he approaches the regions recently left dry by the Caspian, where saline clays, bearing a few Salsolaceae, or mere sand, take the place of the black earth.
As the Gobi desert is approached the forests disappear, the ground becomes covered chiefly with dry Gramineae, and Salsolaceae make their appearance.
Good pasture grounds are only found near the streams. The soil is dry gravel and clay, upon which bushes of Ephedra, Nitraria and Salsolaceae grow sparsely.
But as soon as the soil loses its fertile humus it produces only a few Phlomis, Alhagi camelorum, Psammae, Salsolaceae, Artemisiae, Peganum and some poppies and Chamomillae, but only in the spring.
All of these were originally salt-steppes, and, where the soil is still highly impregnated with salt, have only a sparse covering of shrubs, mostly members of the Salsolaceae, with thick, greyish green, often downy leaves.