How do plants primarily adapt to water scarcity?

Plants primarily adapt to water scarcity by developing deeper roots. This adaptation allows them to access water sources that are located further underground, which is crucial during periods of drought or when surface water is limited. By reaching deeper into the soil, plants can tap into moisture reserves that are not available to other plants with shallower root systems.

In contrast to other potential adaptations, such as evolving thicker bark which may help protect against water loss in some species or environments, or increasing leaf surface area which typically promotes photosynthesis but can also enhance water loss, developing deeper roots is a direct strategy to secure necessary water resources. Altering flower colors is usually related to attracting pollinators and does not directly contribute to a plant's ability to cope with water scarcity.