This is the same plant. On the left, due to a lack of water in the soil its cells are temporarily surrounded by a hypertonic medium. The cells have collased. After watering, the cells become turgid and the plant recovers as seen in the image on the right.

Plant cells are typically surrouunded by in a hypotonic medium. The net movement of water into a plant cell is stopped by the static pressure exerted by cell wall. This turgor pressure makes herbaceous plant tissues rigid (crisp).