Habitat and Ecology
​Selaginella lyallii is a species of spike moss (lycophyte) native to Tropical and Subtropical regions. While highly specific data on its exact distribution is scarce, like most members of the genus, it is a terrestrial plant of the tropical rainforest floor and other deeply shaded, humid habitats. It thrives in constantly moist, organic-rich soil, relying on high atmospheric humidity and protection from direct sunlight, often forming intricate mats in the dark undergrowth of forests.
​Description
​This plant is an evergreen, herbaceous perennial that typically displays a creeping or mat-forming habit, with stems that lie close to the ground and are profusely branched. It is a vascular plant that reproduces via spores. As a member of the subgenus Heterophyllum, it features dimorphic leaves (microphylls) arranged in four ranks: two rows of smaller, appressed median leaves and two rows of larger, spreading lateral leaves. The fine, scale-like leaves create a dense, moss-like texture with a lush, vibrant green colouration. Its intricate branching pattern gives the foliage a delicate, lacy, or feathery appearance, making it an excellent textural ground cover.
​Cultivation
​Selaginella lyallii is an ideal plant for a terrarium, or humid display cabinet due to its absolute requirement for consistent moisture and high humidity. It needs bright, indirect light or shade; direct sun exposure will cause the foliage to rapidly turn brown and shrivel. The substrate must be well-draining, rich in organic matter, and kept perpetually moist; use a mix of humus-rich compost, perlite, and a small amount of synthetic peat or coir. The shallow roots are highly sensitive to drying out. High humidity (70% or higher) is vital for its health and appearance.
​Optimal Daytime Temperature:  18 - 24 °C (64-85 F)
​Minimum Temperature: Must be kept above 10 (C) (50°F); ensure it is protected from cold drafts.
​Water frequently with room-temperature water to keep the medium damp but not saturated. Fertilise very lightly (highly diluted liquid feed) once or twice during the peak growing season (spring/summer).
​Unique Features
​This species is prized for its ability to quickly form a lush, deep green carpet, providing a superb low-lying textural contrast to taller tropical plants. It's fine, upright and flat foliage gives a distinct tall lacy appearance which only a couple of other species resemble, creating a miniature, prehistoric forest floor in any enclosed display. Like all spike mosses, it offers a fascinating glimpse into the world of ancient vascular plants.
​Specifications
​Plant Size: 1-3 stems with the 'flat' top that makes this species visually appealing
​Plant Family: Selaginellaceae
​Plant Passport: A Selaginella lyallii B 140084 C [user input] D GB