Anatomy and Ecology of Grasses

Grasses, or Poaceae, are ubiquitous plants, forming the foundation of many ecosystems. Over 11,000 species exist, adapted to diverse climates from lush wetlands to arid deserts.

Grass roots are often fibrous, creating a dense network that stabilizes soil and absorbs water efficiently. Some grasses, like bamboo, have rhizomes that spread horizontally for asexual reproduction.

The culm, or stem, grows from the base and is typically hollow, except at nodes where leaves and buds form. This structure allows resilience and regrowth after events like grazing.

Grass blades are narrow with parallel veins, optimizing light absorption and reducing water loss. A silica layer often coats them, deterring herbivores and minimizing wear.

The flowering part of grass, the inflorescence, varies greatly among species. It can be a spike, panicle, or raceme, containing florets that house the reproductive organs.

Grass seeds, or grains, are dispersed by wind, water, or animals. Unique mechanisms like the twist of awns in response to humidity help bury seeds in the soil for germination.

Grasses not only prevent erosion and sustain wildlife but also sequester carbon. They are vital in agriculture, with species like wheat, maize, and rice being staple food crops.

Fossilized grass phytoliths found in dinosaur coprolites suggest grasses existed over 66 million years ago, challenging previous beliefs about their evolutionary timeline.