Latin stellatus, starry, in fern hairs referring to bearing 3 or more arms or rays from a central point or stalk, but meaning not apparent for this species.

Plants terrestrial. Stems ascending to erect from decumbent bases, unbranched or sparingly branched in lower 1/2 and much branched above, to 100 cm long, straw-colored, with scattered swollen joints along stem; branches forming an open, ovate, frondlike pattern; rhizophores long, confined to lower 1/3 of main stem, 0.5-15 cm long, 0.5-1 mm in diam. Sterile lateral leaves asymmetrically ovate to narrowly oblong, 2.5-4 x 0.75-2 mm, smaller on branches, margins entire, tips pointed; median leaves lanceolate to ovate-lanceolate, smaller, 1-3 x 0.25-1.5 mm; fertile leaves monomorphic, narrowly ovate, keeled, tips acute; strobili terminal on branches, 1-2.5 cm long.

Growing in solid stands over cliffs and trail sides in 'Akaka Falls State Park, Hawai 'i. First collected in 1969, this plant is likely to spread widely and aggressively, probably initially in adjacent valleys along the Hamakua coast of the Big Island. Native to Mexico and Central America.

There is another articulate Selaginella growing in 'Akaka Falls State Park. It also has swollen joints but differs from S. stellata by having rhizophores scattered along the entire length of the stem, as well as in other characteristics. Attempts to identify it have not yet been successful.

Selaginella stellata may be recognized by its swollen joints scattered along the main stem and by its long rhizophores borne along the lower 1/3 of the stem.