Answer:
sunlight
Step-by-step explanation:
Undergrowth plants can be defined as the undergrowth or undergrowth that is found within tropical rainforests, also occurring in temperate forests, which forms a vital ecological niche in the forest ecosystem to which it belongs. In this highly humid system shaded by dense upper vegetation predominates the trees, shrubs, terrestrial epiphytes, mosses, fungi and other hundreds of hydrophilic species (which need a humid environment), forming exceptional and specific conditions for the maintenance of thousands of animals. .
As you may already know, plants need a lot of sunlight to stay alive. Undergrowth plants, however, are constantly shaded by tall planes, which could be a problem if these plants had not developed adaptive mechanisms to capture and need limited sunlight.