The resaturation of gradually dehydrated shoots was assessed and the sublethal water saturation deficit calculated in plants collected in savannas and in submontane grasslands in Cuba. The critical values of water saturation deficit varied from 30-75%. Some plants show permanent restrictions of their water turnover, avoiding critical water loss from their tissues. Others retain high tolerance to dehydration of their tissues by enlarging their water capacity, which implies an oversaturation effect.