2. The Red Mangrove

The Red Mangrove

(Published in the newspaper Amigoe on the 27st of August 2025)

In the last part, we already mentioned the four types of mangroves that grow on Curaçao. These are the red mangrove, the black mangrove, the white mangrove, and the buttonwood. Now, let’s talk about the red mangrove. It’s the closest to the coastline. 

Name

Have you ever wondered if the red mangrove is actually red? Well, it’s not really red on the outside. But the stilt roots can have a reddish-brown or reddish-purple color when they’re young or just got wet. And if you cut open the bark of the branches, you’ll see a reddish inner layer. This color comes from tannin (a bitter substance). Tannin protects against insects and rot. It also has an antibacterial effect. For example, the dividivi pods also contain tannin. Tannin is used to tan hides and make leather. On many Caribbean islands, including Curaçao, the red mangrove is traditionally used to preserve fishing lines. It’s the tannin in the red mangrove that gives it this preservative effect.

The red mangrove is known as “Rhizophora mangle” in Latin and “Mangel di tam” in Papiamento. The name “mangle” might come from the Spanish words for mangrove, “mangle” and “manglar”. But the origin of “tam” is a bit hazy.

 Manner of growth 

The red mangrove reproduces sexually. The flowers pop up in the leaf axils. Usually, there are two or three flowers together. They’re yellow or greenish white. Each flower has four sepals and four petals. The seed starts to sprout while it’s still hanging on the tree. An elongated seedling grows inside a little casing. That casing with the seedling is called a propagule.

 

Propagule red mangrove

The propagule is about 4 to 12 inches long. When it’s big enough, it falls into the water. If it falls into the mud with the pointed end, it can root right away. If it falls into the water, it can float for a while and roots as soon as it hits the mud. The propagule is green so it can make its own food through photosynthesis. In the plant cells of the propagule, sunlight helps make sugar. This sugar is food for the seedling to survive while floating in the water.

 

 Flowers and forming propagules of the red mangrove in the Curaçao Rif Mangrove Park

Propagules red mangrove in the Curaçao Rif Mangrove Park

Stability

Mangroves thrive in the muddy tidal zones, but growing in mud isn’t a walk in the park. The mud offers little support, and a tree rooted in mud can easily topple over. That’s why red mangroves have these unique stilt roots for extra support. These stilt roots are easily recognizable and are the image many people have of mangroves. They grow downwards from the trunk and branches, giving the mangrove a distinctive appearance.

The stilt roots support the mangrove tree so that it is less likely to fall over. You can compare this to the buttress roots of trees in the rain jungle. In the rain jungle, the top layer of soil is super fertile, but the soil underneath is often poor and hard. Since the layer where the roots grow is relatively thin, trees in the rain jungle can also easily topple over. That’s why tall trees in the rain jungle often have buttress roots at their sides. These roots provide extra support to the tree, just like the red mangrove’s stilt roots do.

 

Stilt roots red mangrove

Buttress roots of a Ficus tree in the crater of the Quill volcano on St. Eustatius

Salt resistance

In the previous article, we learned that red mangroves thrive near the sea, where the soil is salty. But how do they survive such harsh conditions? Well, red mangroves have a clever trick up their sleeves! Their roots are like little filters, removing most of the salt from the water before it even reaches their roots. And guess what? They can even get rid of excess salt by producing special leaves called “sacrificial leaves.” These leaves absorb the salt and die, but the tree doesn’t mind. It uses another leaf from the same branch for absorbing the salt, and the first leaf grows back.

Respiration of the roots

Red mangroves thrive in waterlogged soil, where the water has squeezed out the air from the tiny spaces between the soil particles. So, how do the roots breathe? That is where the stilt roots come in handy. These roots have tiny holes called lenticels that allow them to breathe in air. But here’s the catch: the stilt roots grow downwards from the trunk or branches, so they don’t connect to the underground roots directly. So, how does the air get to the underground roots? Well, it travels through a spongy tissue inside the stilt root and the trunk, all the way down to the roots. That’s why red mangroves are able to grow so close to the sea. The stilt roots stick out so far above the water that the mangrove roots can breathe even when the tide comes in high..

In this article the red mangrove was discussed in detail. The black mangrove will be the topic of the next article. The black mangrove grows a bit further inland than the red mangrove.