Nicholas School Internship Blogs

A Cheat Sheet for Tropical Trees in Ivindo
by -- July 7th, 2015

Well, if you are ever surrounded by an afrotropical jungle and are wondering about all the beautiful trees around you, here are some common, beautiful and amazing wonders of nature that you should stop and stare at.

  • Musanga cecropoides (Parasolier)

A common tree in villages and along roads, Musanga cecropoides grows in disturbed and fragmented areas. It is one of the most familiar trees of the Afrotropical forests, with unmistakable canopy forming what I call nature’s own umbrella against the heat. Its smooth pale grey bark is straight and support thin branches, which are in the form of a candelabrum. The curious looking fruit has numerous tiny seeds that are eaten by primates, bats, birds and humans.

Nature’s umbrella against the glaring sun – Musanga. (Photo courtesy Megan Sullivan)

  • Scyphocephalium ochocoa (Sorro)

Belonging to the Myristicaceae family, I can identify this tree because of its dark red flakey bark that is blotchy with lichens. Also, it bleeds a red watery sap when cut, reminding me of bloodshed, tears and sorro(w)! The large yellow fruits have thick, resinous flesh that encloses a single large, flattened seed. This seed is slightly aromatic and used occasionally to flavor sauces.

Sorro bleeds a red watery sap when cut through

  • Omphalocarpum procerum

This is one of the tree species belonging to the Sapotaceae family, that is a beautiful example of ‘cauliflory’ (did you read that as cauliflowery?). By this I mean that, this tree produces huge yellow fruits weighing about 2 kgs that grow on the bark of the tree. Meant to be a special adaptation for pollination by ants that crawl up and down the bark, these fruits fall down with a resounding thud and contain 20- 30 seeds. This fruits have hard outer shells that can only be cracked by elephants. The inner side of the shell has hard nodules that prevent the elephants from grinding the fruit and damaging the seeds. Considering that elephants are the key dispersers of this species, when heavily poached, the fruits of this tree just sits on the ground and rots, not allowing it to reproduce. It reminds me of the complex web of interactions between plants and animals that are important for ecosystem functioning and conservation.

The adaptation of fruits growing on the bark of trees is called cauliflory and is characteristic of Omphalocarpum procerum

  • Uapaca heudelotii

The only way I can identify this species is because of their weirdly cool stilt roots that are characteristic of mangrove vegetation. Considering that I have seen these in areas that are not marshy, it makes me wonder whether the surrounding areas were flooded once upon a time. The fruits are green bobbles on branches that have three characteristic seeds. When fruiting, these seeds are commonly found around the tree as monkeys and parrots spit them out. Many other animals, such as elephants, gorillas, chimps, myriad of birds and duikers also eat these seeds.

The stilt roots of Uapaca stand tall and mighty (Photo courtesy Megan Sulllivan)

  • Dacryodes edulis (Atanga)

One of my favorite forest fruits, Atanga is grown around many of the villages here. They hang in large bunches and are bright pink when young, but turn blue back when ripe. Always boiled for a few minutes before eating, the fruit are a weird conglomeration of an olive and an avocado (imagine that) and goes really well with salt or piedmont! I do not know much about its dispersal network, but I would not be surprised if monkeys, gorillas and chimpanzees visit this tree species.

A perfect snack after a hike- avacado and olive together gives an Atanga

  • Lophira alata (Azobe)

One of the most obvious trees during the month of December, Lophira alatai goes bare for a brief period of time and bursts into red young leaves giving the feeling of Christmas in the hot tropics. These leaves slowly fade to pink, peach, yellow green, to pale green and finally become dark green when mature. Unfortunately, I will be unable to see this spectacular display of colors making it one of the most different and beautiful trees of the forest.

A glimpse of yellow amidst the deep, dark green of the forest (Photo courtesy Megan Sullivan)

  • Aucoumea klaineana (Okume)

This is one of the first trees I learnt when I arrived and is probably the most famous tree species here. Its claim to fame is that it accounted for the majority of timber exports back in the day. Since the logging industry is the main means of livelihood to many Gabonese, Okume is an important source of income. In recognition to its contribution to the economy, many stamps have also been issued. When injured, the bark of okume secretes a sticky and clear resin that solidifies when out in the open. This solidified resin almost feels like wax and also burns brightly, hence being aptly used as a fire lighter when camping. Unlike other tropical trees, not many animals depend on okume for food. I have heard that it is listed as a protected species now and I think it will be an important natural resource that will need strict management and conservation strategies if logged further for timber.

The wide buttresses that fortify the Okume (Photo courtesy Megan Sullivan)

  • Bailonella toxisperma (Moabi)

Some of the trees of this species are the biggest I have seen here. With diameters as big as 3m and over 70m tall, Moabi has slowly entered the timber market. The seeds are heated and compressed to give its valuable oil that is nutritious. Selective logging is said to have made this tree species rarer and poaching of elephants is also posing a big problem, as the elephant is its main disperser.

  • Coeclcaryon pruessi

The shiny black seeds of this tree are the first I saw with a bright pink aril. This thin aril is rich in oil, which many animals depend on. Fruiting right now, this tree species is considered to be a ‘keystone species’ as it fruits during the dry season, when overall fruit availability is low and hence supports the animal community. My first tryst with this tree was when I was following a group of monkeys and mandrills and I came upon the bright pink remnants of the aril in the midst of the burgeoning forest undergrowth.

  • Tetracera alnifolia (the only non-tree in this list)

I can only identify a couple of lianas here and the one that stands out to me is Tetracera alnifolia or the ‘water liana’. This deceiving (and at least hard for me to identify) liana can be the best friend you wished for having hiked without water. When cut across, it showers you with water. The fruit (yeah, lianas have fruits as well) is oval shaped and pale green when ripe with short white lines across, almost reminding me of tick marks. When split open, it actually secretes this watery liquid and has about 3-4 round, pale yellow seeds.

 

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