**Selaginella diffusa** is a tropical clubmoss species native to Central and South America, where it grows along moist forest floors, riverbanks, and shaded slopes. It is known for its delicate, trailing to creeping stems and finely divided, feathery foliage that forms soft, spreading mats. This species thrives in high humidity and shaded environments, making it a popular choice for terrariums and paludariums.

**Light Requirements:** Low to medium, bright indirect light preferred. Avoid direct sunlight.
**Humidity Requirements:** Very high, ideally 80–100%. Requires consistent moisture and humidity to prevent frond desiccation.
**Temperature Range:** 68–85°F (20–29°C). Does not tolerate cold or dry air.
**Growth Habit:** Creeping to softly ascending; forms dense mats that root at the nodes.
**Soil:** Moist, humus-rich substrate with excellent drainage such as sphagnum and perlite mix.
**pH:** Slightly acidic, around 5.5–6.5.
**Size:** Typically 5–15 cm tall, spreading extensively across surfaces.