Cecropia trees are strange and wonderful tropical rainforest trees from Central and South America.
Russell Fransham demystifies cecropia
Fifteen years ago, I planted a tiny seedling of Cecropia peltata in the garden and within two years it was 6m high with a hollow trunk, no branches and big palmately lobed leaves about 60cm across. And now at 10m, it has an umbrella-shaped canopy and the smaller, segmented side branches are filled with gloopy mucilage while the snake-like roots run across the lawn bulging above the soil. One of its many common names is snakewood tree.
There are about 60 species of cecropias throughout tropical America.
They are pioneer plants (like New Zealand’s manuka) which colonise bare ground, then die away once they’re shaded out by larger trees.
They are a dominating presence in tropical America‘s humid forests. Their improbably fast growth is their winning formula in the race to get above any competing trees whenever open space is created by a disturbance such as roads, landslides or fallen canopy trees. So they tend to live fast and die young(ish), and in their race against time, will start to flower and fruit as soon as the candelabrum-like branching system starts in the second or third year.
Cecropias are dioecious, which means the sexes are on separate trees so at least one of each sex is needed to do the business.
Bizarrely, they are most closely related to nettles which are a branch of the fig and mulberry family Moraceae, and their distinctively sculptured leaves have an unmistakeably figgy look.
While many of the cecropias are fully tropical, Cecropia peltata comes from the cooler altitudes of the Andes mountains where it is an important component of the cloud forest. Tolerant of cool temperatures, it grows readily in Auckland and Northland though its big sculptural leaves are easily damaged by frost.
Cecropias are known as myrmecophytes, which is fancy talk for “ant trees”.
Most of the local names for cecropias refer to their relationship with ants.
There are several species of predatory Azteca ants in tropical America that can live inside the hollow sections of their trunks.
The tree even provides supplementary food for the ants in the form of pellets of glycogen called ‘Müllerian bodies’, secreted by hairy glands on the leaf bases. These hairs (trichomes) are just like stinging nettle hairs modified to secrete this sugary ant food instead of stinging acids. Glycogen is the principal storage carbohydrate found in animals and is extremely rare in plants. In return for these services, the ants defend the trees from other leaf-eating animals such as leaf-cutter ants, locusts, birds and even monkeys. They will even attack vines that try to climb their cecropia host.
The only animals the ants can’t persuade to jump ship are sloths whose main food is cecropia leaves as they seem to be unaffected by the ants’ frantic biting.
Here in my garden, the wood pigeons have discovered that young cecropia leaves are very palatable.
They strip the tender green parts, leaving the leaf veins intact when their usual foods are in short supply. Of course, the fearsome cecropia ants are not here in New Zealand, so these trees are a great standby for lean times in kereru world.
For those of us who aspire to planting a backyard food forest, Cecropia peltata provides fast cover for other subtropicals and produces rather tasty, if unusual fruit. They are vaguely banana-shaped and yellow-brown when ripe, with an outer crust of tiny seeds covering a softer custardy interior. These are eaten fresh or made into a delicious brown jam that looks and tastes like fig jam.
In Latin America, cecropias are famous for their multitude of medicinal uses.
Every part of the tree is used to treat a wide range of different human ailments, from cardiac, liver and lung disease to Parkinson‘s and diabetes.
Its anti-inflamatory and antibiotic properties are so legendary, it is considered an essential medicine chest in rural areas throughout the forested areas of the continent.
The bark is also made into durable rope while the rings of hard white wood are made into musical instruments, boxes, toys and rafts, and the mature leaves are used as sandpaper.
And to top it off, if you like smoking things, you could even smoke the dried leaves which apparently taste like a smooth, slightly stimulating tobacco… without the nicotine! ✤
Male Cecropia peltata with flowers and wood pigeon damage.
Ants eat the glycogen pellets, called MÜllerian bodies, secreted by the hairy brown gland at base of the leaf.