Wedge Mega

The only other nutrients needed by most green plants are minerals such as nitrogen, phosphorus, and potassium, which also can be absorbed directly and require no digestion.

Both compounds can be absorbed easily across the membranes of cells—in a typical land plant, carbon dioxide is absorbed from the air by leaf cells, and water is absorbed from the soil by root cells—and used directly in photosynthesis; i.e., neither of them requires digestion.