ECOSYSTEM CHAPTER 14 BIOLOGY - NEET MCQ

Psammophytes a plant that thrives in shifting sands, primarily in deserts. Psammophytes are marked by a number of adaptations that enable them to exist on wind-blown sands. In such an environment, the plants are often covered with sand, or their root system is exposed. It is also difficult for the seeds to germinate. Psammophytic trees and shrubs form strong adventitious roots on those parts of their trunks buried in the sand (Haloxylon persicum, Calligonum); adventitious buds and, then, shoots arise on the exposed roots (Ammondendron, Eremosparton, Smirnowia). Herbaceous psammophytes form underground shoots (Aristida) on long, fast-growing rhizomes that sprout through the sand (Carex areharia).
Many psammophytes are xerophytes and annual ephemerals. Perennial psammophytes have small, very reduced leaves or no leaves at all; photosynthesis and transpiration are accomplished by the stem (Haloxylon, Calligonum). The fruits have appendages in the shape of wings (Haloxylon), propellors (Ammondendron) or parachutes (Aristida) that enable them to move with the sand and to remain on the sand’s surface. After seed germination (usually in early spring), the roots grow very quickly, soon reaching a depth of approximately 0.5 m. At this depth, the sand remains moist until the onset of summer.
Psammophytes are encountered not only in deserts but also along seas and large lakes and in sands along rivers (Elymus giganteus, sand fescue, sharp-leaved willow). Psammophytes are often used to stabilize sandy soils.