Occasionally, large plants like trees, shrubs, or cacti can be found growing in the cracks of broken or weathered boulders. Life for these plants tends to be shorter than average because the relatively small growing space of the rock crevice provides very limited food and water for the plant, and when the plant becomes too large, its needs will exceed supply, and the plant will die. Its death will add more organic matter to the rock crevice and the next plant to grow there will live longer with this additional food.
Here, a small bush is growing in a large, broken rock amidst the remains of another bush that had grown too large to survive.
Decaying plant matter is acidic and will gradually eat away the rock. It also holds water, and because water expands as it freezes, this can cause the rock to fracture even more. This cycle of plant replacing plant in the rock will continue until the rock finally crumbles from both plant-assisted weathering and the relentless pressure of plant roots pushing into every fracture in the rock.