A Neotropical Savanna

The more I learn about the Myrtle family of plants, the Myrtaceae, the more interesting it becomes to me. I already mentioned when writing about the Eugenia berries that members of the family include clove, guava, allspice, and eucalyptus. You can see from this list that the aromas can be quite spicy or strong. Now add to this list the aromatic wax bay berry and and the wax myrtle plant. These waxes are produced by plants in the genus Myrcia. The fruit surface of these plants is rich in palmitic acid – a fatty acid commonly found in animals and plants, according to wikipedia. The wax is removed in boiling water. Early settlers in the US made candles this way (Mabberley).

The unidentified tree in the gully, the one with the galls on it, belongs to this genus Myrcia. It was identified by a specialist in the Myrtaceae family at the Field Museum in Chicago, Lucia Kawasaki, and its full scientific name is Myrcia splendens. The potential waxy coat on the surface of this fruit is hinted at by its shine in the tree and perhaps even more so when seen close-up in a scan of fruits in various stages of ripeness:

However, Carrasquilla, the author of Trees and Shrubs of Panama, makes no mention of the use of the fruit for wax. He says the fruits are edible, sweet, and astringent. I think they’re sweet and spicy – maybe a little like allspice – but did not find them astringent. The bottom item in the scan, by the way, is the seed, not a small fruit. From that you can see that there’s not much pulp to the fruit. The seed is delicate and it’s easy to crunch right through it, thus destroying any pleasure from the sweetness of the fruit.

Carrasquilla, lists the distribution of the Myrcia splendens as being from Mexico to Peru and the West Indies, which corresponds to this distribution map from the Global Biodiversity Information Facility.

The species is listed at the US Department of Agriculture Plant Profile web site because of its presence in Puerto Rico and the Virgin Islands.

Just how splendid Myrcia splendens can get may be imagined from its listing in the Champion Trees of Puerto Rico where one such tree located in the Sabana Grande (the Grand Savanna) and last measured in 1966 was found to be

• 39.1 inches in circumference
• 41.0 ft in height and with a
• 25.5 ft crown spread.

I’ve measured only the circumference of the tree in the gully – it’s 19 inches around, so it’s a long way from challenging the champion.

One characteristic of the Myrtaceae family is a papery thin bark, epitomized (to me) by Eucalyptus bark (left image). So one of the reasons I was unsure of placing the gully tree into the Myrtaceae family was that its bark was coarse (right image). Once the Field Museum botanist identified the tree, though, and assured me that here was an exception to the guava-bark (guava being another myrtle and probably worth another post at some point) appearance, I put away my doubts.

To review

From the Eugenia post, plant may be a member if the Myrtaceae family if it has

• simple, opposite leaves with smooth margins
• punctations (translucent dots) on the leaves
• thin, peeling bark (usually)

To learn

A plant in the Myrtaceae family may be a member of the genus Myrcia if it has (Gentry)

• a well developed central axis to the inflorescence (flower cluster)
• usually has a set of young buds that look like stipules at the end of a twig
• may have hairs (trichomes) that look like Malpighiaceae hairs

Here are each of those traits on the gully tree:

The strong central axis.

Stipule-like buds at end of stem.

Malpighiaceae-like hairs. The Malpighiaceae family includes one of Panama’s favorite fruits – the nance. In these two images, the myrtle leaf is on the left (or top, depending on your browser) and the nance leaf is on the right (or bottom).

As for why this Myrcia is of the species splendens, this I have not been able to find out. The web site Trees, Shrubs and Palms of Panama lists 3 species of Myrcia (not splendens, however, although M. splendens is listed in the Flora of Panama Checklist as well as in Carrasquilla, of course).

One last tidbit on the Myrtaceae family pertains especially to our neotropical savanna/abandoned pastureland. Barwick, in the beautiful book Tropical & Subtropical Trees, says that the typical habitat for the slow-growing Myrtaceae is tropical American pastureland. Just for kicks, here’s the pasture just on the other side of the stone wall from our gully tree. No trees in that pasture, but our once-pasture was adjacent and nearly all of our trees spring up in abandoned pasture land. Myrcia splendens among them, I’ve just learned.