Moss is a small, soft plant that grows in dense green carpets on rocks, tree trunks, and damp ground. Unlike many plants, moss has no true roots, flowers, or seeds. Instead, it anchors itself with tiny thread-like structures and spreads by releasing microscopic spores into the air.

Moss thrives in moist, shady places where other plants struggle to grow. You'll find it covering fallen logs in forests, creeping up the north side of trees, and cushioning the stones around streams. When you touch moss, it feels spongy and damp, like a living carpet. Some types can absorb water like a sponge, holding up to twenty times their dry weight.

The saying “a rolling stone gathers no moss” means that people who keep moving and changing direction don't accumulate responsibilities or long-term commitments. Whether that's good or bad depends on your perspective: some see moss as a sign of staying put and building something lasting, while others see it as getting stuck in one place.

Moss has existed for over 400 million years, making it one of Earth's oldest plant groups. Scientists study moss to understand how plants first moved from water onto land.