How have the vegetation of thorn forests adapted to the climate?

How have the vegetation of thorn forests adapted to the climate?

The Thorn forests are found is the region with less than 70 cm rainfall.
The adaptive features of vegetations of thorn forest are
(i) Roots are long which can penetrate deep into the soil to get moisture.
(ii) Stems are succulent to conserve water.
(iii) Leave are thick to minimise evaporation.