Red mangrove
In Jamaica, the red mangrove occupies fringing to intermediate tidal zones. The species gets its name from the dark red color of its wood which is covered by grey bark. This evergreen tree is the tallest of the mangroves, growing to over 25 m high with a 40 cm diameter at breast height. Rhizophora mangle has pointed broad leaves (12 cm) that are waxy and bright green on their upper surface and paler on their underside. Both the species’ trunk and branches exhibit prop roots that reach downwards but only penetrate a few centimeters into the ground. This shallow rooting system and stabilizing prop roots are adaptations to the dissolved oxygen depletion of anoxic soils. Many small pores called lenticels perforate the above-ground roots, diffusing oxygen even underground and preventing water from entering the tree during high tides.
The red mangrove bears pale pink flowers and fruit yearlong. The species’ seedling, called a propagule, has an elongated cigar shape approximately 1.25 cm in diameter and can grow up to 30 cm long. Rhizophora mangle is viviparous: propagules develop continuously, without a dormant or sàseed phase, from flower to germinated seedling while still attached to the parent tree. Once they fall from the parent plant, propagules complete their development in seawater for approximately 40 days. However, they can float in search of suitable substrata for much longer, at times more than a year, without rooting.
Red mangroves colonize the intertidal zone, thriving in soft muddy soils along river banks and estuaries. The species’ complex rooting system represents the first seaward line of defense against wave action. Red mangroves are usually found in association with black mangroves and white mangroves that occupy slightly higher tidal elevations.