A Neotropical Savanna

In June we experienced a record rainfall of 43 inches. The previous record was 41 inches and the average for this area is 22 inches in June. Here’s a graph of the erratic 2010 rainfall (red line) compared to a 16-year average (blue line).

Back in May, I noted the early blooming of Miconia rubiginosa after the heavy rains in April.

Now, in July, I’ve seen two plants in bloom that I normally see bloom in August: a tree with large bunches of yellow flowers, Senna hayesiana, and a miniature relative of the Elephant Ear herb, Xanthosoma mexicanum. I’m also seeing flower buds on an unidentified Miconia that usually blooms in September. I’m sure more’s going on along this line than I’m seeing.

Maybe these large swings in time of blooming are relatively normal for the tropics. But I’m starting to think that it’s more than coincidence that different plants from three unrelated families (Senna = Fabaceae or bean family, Xanthosoma = Araceae or arum family, Miconia = Melastomataceae or “black mouth” family)  are blooming immediately after uncommonly large monthly rainfalls.

The corotú is one of the largest and most beautiful of the trees of the savanna (left photo, below). It is known in Costa Rica as the guanacaste and is the national tree of that country. It is also known as false mahogany, the earlobe tree, and the elephant ear tree, among other names.

The gomphothere is an extinct large mammal, with four tusks and some elephant-like features. The illustration at right below is from Fossil Treasures of Florida, used by permission.

How the corotú and the gomphothere are related is a fascinating story uncovered by Janzen and Martin while working in Costa Rica, and we’ll get to it shortly.

How to recognize the corotú

The corotú is an intriguing tree in its own right. As a member of the Fabaceae (bean) family, it has alternating, compound leaves and produces pods filled with beans.

The tree itself may grow to 35 meters (about 115 ft) and its trunk may exceed 1 meter (3.2 ft) in diameter. The trunk of this particular roadside tree is covered with woody vines, nearly hiding its light gray color and dark, reddish brown vertical fissures.

But the sure-fire key to recognizing the corotú lies in its distinctive pods.

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Yesterday Steven Alexander of Tropical Biodiversity published a beautiful image of a Senna tree in flower. It was incentive enough for me to go look at our own Senna, Senna hayesiana, which has been in bloom since August.

The pre-dawn light and my camera settings make the flowers look a brighter yellow than they are. Imagine a paler shade. If you have Steven’s image up for comparison, the color of the Panama flowers are somewhere between the two images.

This particular Senna is among the few trees in our area that are in bloom this time of year, and because they tend to grow at the edge of woods, their color really stands out against the various shades of green.

Or, for that matter, against the brown of a rock wall or the blurry brown of a Lab in motion.

The flowers are pollinated by insects. There’s a Senna hayesiana behind our bodega, near our compost bins. If the tree is in bloom when I empty the compost into the bin, I inevitably hear the buzzzzzz of bees. This morning I saw a bumblebee nearly half as large as the flower itself, but of course, I had a compost container in my hand rather than my camera.

I do have a picture from three years ago of a bee at work on the flower, but I’m putting it after the break because the color of the flower is so jarringly different from the colors in today’s images. (Camera differences, ambient light conditions, among other variables – I’m not knowledgeable enough with photo editing software to make color corrections.)

You’ll see the bee poised at the end of the green, curved pistil, the female reproductive structure.

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John Bennett reported in December that the algarrobo tree was preparing for the dry season by changing to brown dry season leaves which he assumed had fewer stomata and therefore would lose less water than the green leaves. Here are the brown leaves.

He’s been keeping an eye out on this tree for us, and I thought I’d pass along to you his report.

Ok… time to update on the algarrobo garment renewal…

Here is the algarrobo with its new set of green chemistry labs, ready to process winter mineral carrying fluids from the ground and continue reaching out to the sun.

Nice tree, isn’t it?

Here is a closer look at the chlorophyll labs, and… what is that brown thing amidst the leaves?

Let’s take a a closer look…

Looks like some nectar sucking poisonous flying bugs have set up residence among the new foliage. A closer look at the creatures shows them peeking out their residence’s aperture. Wonder what they make of the camera flash?

Before getting entranced with the wasps, I’ll pipe in here with a reminder from John’s first report and also a couple of other observations.

In his first report, John told us that the scientific name of the tree is Hymenaea courbaril. and that it is in the family Fabaceae, subfamily Caesalpiniodieae.

Fabaceae is the bean family, which means the tree has compound, alternate leaves. If you need a refresher, there’s a pretty complete description of the bean family in the post on macano, The Living Fence. In the case of the algarrobo, the compound leaves consist of two leaflets. The subfamily is the one with the large frilly flowers, such as the Flamboyant tree.

The genus name, Hymenaea, is named for Hymen, the god of marriage. It refers to the leaflets, which occur in pairs (Botanary). The species name, curbaril, is one of the common names for the wood of this tree (Vozzo).

The tree that has just now put out green leaves will flower starting in March and continuing through July. The fruits will ripen the following year, between February and May (Carrasquilla). If you go back to John’s first image, the one with the brown leaves, and click on it to enlarge it, you will see a large kidney-bean shape in the tree. That’s last year’s fruit, due to ripen any day now.

Here’s what John has to say about the tree and its fruit:

It is an extraordinary tree, in many respects; and the fruit is one of the richest food sources you can find. Some people don’t like the smell, or taste, but I was brought up with it. When you open one of the pods, take the dry fleshy pits out and take a good sniff of the inside of the pod… I find it wonderful. But I don’t care for Roquefort or such.

So it’s about time we started watching for the fruit at the local markets, yes? And see for ourselves if we like it, yes?

Meantime, about those wasps…

There is a great variety of them in Panamá; big, small, mean, docile, with all sort of dwellings, but I have never read anything about them. For example, take a look at another bug aerodrome…

These critters always build their entrance atrium looking south.

And look at these guys… they build into walls and such, and are always curious about who is around their den… A while back I witnessed a war between these critters and ants.

Take a look at this aerial combat, between two varieties of bees…

Anyone who knows anything about the wasps or bees around here is welcome to speak up. These are fascinating abodes.