Water Problem. So how do desert plants conserve water?
1/ By reducing the surface area of the plant to the smallest---Desert plants are usually spherical, with leaves which are modified into spikes, so water loss will be less.
An example is the cactus.
2/ By reducing their stomatal pores---So that the CO2 intake is less, and their growth rate will be extremely slow.
3/ Some species of desert plants grow underground---to avoid the sun and rain.