Tea Mangrove / Palo de sal

Overview

Tea mangrove or palo de sal (Conocarpus erectus) is the salt-tolerant shrub-to-small-tree that closes the inland edge of the mangrove zone on both sides of the tropical Atlantic. Despite the common name, it is not a true mangrove in the strict sense — it belongs to Combretaceae, not to the prop-rooted Rhizophoraceae or to the pneumatophore-bearing Avicennia and Laguncularia. It tolerates salt but doesn’t depend on tidal inundation, so it tends to occupy the drier landward fringe of the mangrove sequence.

Identification: small, gnarled, dense crown; leathery alternate leaves often with a silvery underside in the silver variety (sericeus); inflorescences of tiny greenish flowers; clusters of small, cone-like fruit aggregations — the source of the “button mangrove” name in English. Bark dark, scaly.

Why Tortuguero

In TNP the four mangrove-zone species form a predictable seaward-to-landward gradient. Red mangrove (Rhizophora mangle) holds the waterline with arching prop roots, Avicennia germinans and Laguncularia racemosa occupy the intermediate zones, and Conocarpus erectus — the tea mangrove — closes the sequence on the highest, driest ground. Walking inland from the river mouth, the transition out of true swamp into coastal scrub is often marked by exactly this species.

Mangrove-fringe ecosystems anchor the food web of the river-mouth lagoons that hatchling sea turtles enter on their first hours offshore and that estuarine fish, manatees and crocodiles use as nursery habitat. The integrity of the landward edge — where Conocarpus lives — matters for the stability of the whole sequence behind it.

How to see them (honestly)

• Boat trip near the lagoon mouth and any of the sheltered estuarine bays. Look at the transition from open prop-root forest to firmer ground.
• The tree is unspectacular at first glance — easy to mistake for generic coastal scrub. The cone-like fruit clusters are the give-away.
• Best contrast: walk a stretch where you can see the gradient — Rhizophora at the water, then Avicennia / Laguncularia, then Conocarpus at the back.

Status note

IUCN lists Conocarpus erectus as Least Concern globally — it is widespread on both sides of the tropical Atlantic and reproduces well on disturbed coastlines. Local-scale threats are the standard ones for coastal vegetation: shoreline development, sand extraction, and the conversion of the back-mangrove fringe for tourism infrastructure. Within TNP the species sits in a protected boundary, but the broader Caribbean coast of Costa Rica has lost significant mangrove area over the last fifty years.