Rock Spikemoss

selaginella rupestris

Rock Spikemoss is a resilient, primitive plant that thrives in some of the most inhospitable environments. Belonging to an ancient lineage of vascular plants called lycophytes, it is far more closely related to clubmosses and ferns than to true mosses. This remarkable survivor forms dense, evergreen carpets over sun-baked rocky surfaces, bringing life to stark granite ledges and sandy barrens where other flora struggle to take root. Its defining characteristic is its incredible ability to withstand prolonged periods of severe drought, curling into a dormant, gray-brown ball until rain returns to rejuvenate it. This spectacular recovery showcases the absolute resilience of ancient plant designs in the modern world.

Habitat: Found in dry, exposed rocky outcrops, granite ledges, and thin, sandy soils in full sunlight.

Appearance

This species grows in low-spreading, moss-like mats reaching heights of only 2 to 6 centimeters, though creeping stems can stretch up to 15 centimeters. The foliage consists of densely packed, scale-like leaves that are narrow, dark green to grayish-green, and tipped with a distinctive fine, white bristle. During dry conditions, the entire plant rolls inward, presenting a dusty, dehydrated brown appearance, which quickly unfurls back into a vibrant green carpet upon contact with water. It produces small, square-shaped cones called strobili at the tips of its branches, which contain the spores used for reproduction.

KingdomPlantaePhylumTracheophytaClassLycopodiopsidaOrderSelaginellalesFamilySelaginellaceaeGenusSelaginella

Rock Spikemoss

Interesting facts

Despite its common name, Rock Spikemoss is not a moss but a lycophyte, representing a lineage of plants over 400 million years old.

It reproduces via microscopic spores rather than seeds, carrying out a complex alternation of generations typical of primitive vascular plants.

The tiny white hair at the tip of each leaf acts as a natural sunblock, reflecting harsh solar radiation away from the plant.

Special abilities

The plant can lose up to 90 percent of its water content during droughts and survive in a dormant state, rapidly restoring its metabolic functions and greening up within hours of rainfall.

It curls its stems and scale-like leaves inward when dry, reducing the surface area exposed to the sun and wind to prevent further moisture loss.

Employs specialized, thread-like structures called rhizophores that grow downward to securely anchor the plant onto bare stone and absorb scarce nutrients.