Resurrection Fern

Overview

The resurrection fern (Pleopeltis polypodioides) is a small epiphytic fern famous for one remarkable trick: it can lose up to 97% of its water content during dry conditions — appearing dead, with curled brown fronds — and revive completely within hours of rain, unfurling green again with no apparent damage. Most other plants die at around 8–12% water loss. This poikilohydric capacity is part of what makes it one of the most desiccation-tolerant vascular plants on the planet.

Fronds are small (5–25 cm), simple-pinnate, with scaly undersides; rhizomes creep across bark in dense mats. Spore production is normal Polypodiaceae — round sori in a single row along the leaflet edge. The plant prefers sun-exposed horizontal branches where it can dry hard between rains, which is the opposite microhabitat preference from many of its tropical relatives.

Why Tortuguero

In TNP, the resurrection fern is abundant on sun-exposed major branches of canopy and emergent trees. The lowland tropical climate provides reliable rain, so the species rarely needs to deploy its full desiccation-recovery trick — but the underlying physiology is the same, and during the relative dry season (February–April) you can see colonies enter and exit dormancy on visible timescales.

It’s a useful illustration for visitors of how diverse the epiphyte community of a wet tropical forest is. Asplenium serratum (bird’s nest fern) occupies the deep-humid, debris-trapping niche; Pleopeltis polypodioides occupies the opposite end — exposed, fast-drying, drought-tolerant. The same canopy supports both extremes within meters of each other.

How to see them (honestly)

• Any open-canopy walk — look at the upper sides of horizontal branches on large trees. Dense mats of small ferns with creeping rhizomes are usually Pleopeltis.
• Best demonstration of the resurrection behavior: visit the same branch after a dry stretch and again right after rain. The visible difference is dramatic.
• The fern is easy to confuse at a glance with other small epiphytic ferns; the scaly underside and small simple-pinnate shape are the diagnostic features.

Status note

Pleopeltis polypodioides is Least Concern — the species is widely distributed across the Americas and reproduces well in many forest types. Its tolerance of drought and sun exposure means it persists in disturbed and edge habitats where more demanding ferns disappear, so it is not a useful indicator of canopy quality in the way that Asplenium serratum is. The contrast between the two species is itself the ecological lesson: a healthy lowland forest carries epiphyte specialists across the entire stress gradient, not just at one extreme.