Plants gregarious or tufted, pale green to brownish, straight or curved at tips when dry, to 5 mm or more but mostly much shorter. Leaves dimorphic; vegetative 1-3 mm; distal lamina oblong to broadly linear-lanceolate; margins 1-stratose or slightly thickened distally, entire; costa in cross section showing ad- and abaxial bands of stereid cells; medial cells distinct, 7-8 µm, slightly bulging adaxially, smooth or minutely papillose abaxially; teniolae absent; cancellinae ending in broad angles distally, adaxial cells smooth distally; gemmiferous leaves with apex of costa excurrent, bearing gemmae in pale golfball-like spheres all around on costa apex.
Not producing sporophytes in flora area. Tree trunks and logs in hammock vegetation; low elevations (0 m); Fla.; Mexico; West Indies (Grand Bahama, Haiti, Puerto Rico); South America (s Brazil); Asia; Africa; Indian Ocean Islands; Pacific Islands; Australia.
Calymperes tenerum is very rare in the flora area, where it is known only from a few specimens from southern peninsular Florida. Its absence of teniolae, narrow cancellinae, and gemmae in golfball-like spheres make it distinctive. This species has a very wide distribution in the tropical parts of the world and is very common in the paleotropics; it is extremely scarce in the Neotropics, suggesting that it is an introduction there.