Bonjour
Outside of winter, other circumstances may be unfavorable to the life of the plant, especially drought or excessive heat, that only latent life can overcome.the temporary reduction of activity is called latent life ( dormancy).
In this state, metabolic activities and exchanges are almost imperceptible, limited minimum essential for the production of energy necessary to maintain cellular structures.
this is the case for most ping temperate which, to face the winter, make hibernaculae.
this is also the case for the Mexican ping but to face the hot and dry hot climate,they have accumulated reserves (water, juice), by modifying their appearance with succulent leaves without mucilage, in the form of rosette sometimes arachnoides or restriction of their surface(agnata, gigantea,etc) or even sometimes by making onions( medusinae,heterophylla,oblongiloba)
jeff