In the Amazon rainforest, a number of grass species are introduced and invasive in open areas. Beyond inhabited areas, grasses (Family Graminae) are rare. These plants need bright light and rich soil, and there's not much of that in primary rainforest. For this reason, most wild grasses in the rainforest grow directly in water or close to the water's edge. Grasses are useful to people mainly as forage for cows and goats. However, the most important type of grass is rice, which is widely cultivated. The largest grasses are bamboos, several species of which are common along river edges and lakesides. The biodiversity of Amazon grasses seems relatively low, perhaps because they are outcompeted by more shade-tolerant plants.
Click below for grasses photos and natural history information:
"I believe a leaf of grass is no less than the journeywork of the stars."
Walt Whitman Song of Myself 1855