A rather innocuous-looking shrub bloomed, scantily, recently.
The flowers are appealing, though, and the plant was just calling out for identification.
One look at the stem between the leaves and I knew immediately what family it probably was in. What you’re seeing below is a stipule, a leaflike appendage to a leaf. Often these stipules occur in pairs at the base of the leaf stalk, or petiole. But look closely (by clicking on the image for a larger view) – that appendage is between the petioles. Here in Panama that interpetiolar (between petioles) stipule is an almost sure sign that the plant is in the coffee family, Rubiaceae (Gentry).
In addition, the leaves are simple and opposite each other on the stem, and the margins or edges are smooth, not toothed, further suggesting a member of the coffee family.
The coffee family, however, is one of the largest of plant families in our area (Gentry), so I did not expect to find the name of this plant very readily.
A Costa Rican Key
Luckily, there is a fine and easy to use key to trees of the Guanacaste conservation area in Costa Rica, which is a dry forest area not unlike the forested areas of our savanna. The first characteristics you look at in that key are whether the leaves are simple or compound (simple), the arrangement of the veins (pinnate, like the feathers of a bird – see the image below), and the leaf arrangement (opposite).
- Next, you crush a leaf to determine whether there is any milky sap or latex. (No.)
- Are the edges of the leaf toothed? (No.)
- Are there spines on the young stems? (No – not illustrated.)
- Are interpetiolar stipules present? (Yes.)
- Does the growing tip have two long hair-like projections? (No – not illustrated.)
- Does the underside of the leaf have numerous black dots? (No – click on image above.)
- Are the trunk and branches orange and white, with thin peeling bark? (No, see next image.)
- Do leaf margins have a fringe of hair? (No, see leaves above.)
- Are the leaves lance-shaped and 3-4 times longer than they are wide? (Yes, see leaves above.)
- And finally, do the stipules persist and become papery brown? (Yes)
Conclusion: This plant is Alibertia edulis. It is found in Central and South America.
The white flowers suggest that it might be pollinated by something that is active at night. Further, its trumpet shape suggests that the pollinator has a long antenna. So it’s possible that the pollinator is a moth. But whether by coincidence or not, every time I’ve looked at the flowers, I’ve seen ants around them, and one time I managed to get a snap of the ant headed toward the interior of the flower, as if it were after nectar. Possibly it was a nectar thief – it’s unlikely the ant is actually the pollinator.
As you might guess from the species name edulis, the plant produces an edible fruit. In Brazil,
This common small tree/shrub is called locally ‘marmelo’, a name given by the Portuguese who saw in its fruit the New World approximation of the familiar quince, ‘marmelo’ in Portuguese, and the source of the first marmelade, in our time made mainly of oranges.
Here in Panama, the common names are trompito, madroño, zumbo, guayabito de monte, none of which suggest marmalade, although the names madroño (strawberry tree) and guayabito de monte (little guava of the hills or woods) do suggest that it is edible. I’ll have to watch for the fruits and give it a try.
Nice to see a tropical member of this tropical family. Most of our Rubiaceae in Arizona are small herbs, like Galium . On it, the stipules can be hard to distinguish from leaves.
Here’s a link to an image of Galium: http://tinyurl.com/2csclzj
An attractive shrub, I’d imagine it would be quite beautiful if the flowers were more profuse. Of course, of all the ‘crop’ plants I think coffee is one of the most beautiful with its glossy crinkled foliage.
Hola Mary! This is the first blog entry I’ve seen since your “vacation” from the blog. I see I have some catching up to do from last month. I’m glad to see you back in “investigative” mode.
The coffee family is, indeed, a very large family. I recently learned this on a trip to Isla Barro Colorado. Now, when I’m in the forest, or just on the overgrown edges of my yard which is the forest, I look at plants and shrubs with more curiosity to see which have coffee plant like characteristics.
Hi Shelley,
Well, are those giant stipules in the second picture? Impressive, and thanks for the link.
Mary
Hi Ted,
Indeed, the coffee plant is beautiful. One of these days I hope to get a photo that does it justice. Meantime, thanks for appreciating the Alibertia.
Mary
Hi Michael,
Yes, the coffee family is everywhere here in the tropics, isn’t it? I also look for coffee plant characteristics right away. Like Ted, I find the “glossy crinkled foliage” very attractive. Okay, the leaves are not always crinkled, but the leaves are always very nice, I think.
Mary
By the looks of the flower, you would certainly think the pollinator is a hawkmoth. If the flowers open as evening approaches and produces considerable fragrance that would be another tip off. Many Rubiad flowers have wonderful odors.
Thanks for the tip, Phytophactor. I’ll check this evening. During the day there is only a faint fragrance, but I have noticed that it is rare to see a “young” flower during the day. Many of them already have acquired brown edges.
UPDATE: Yes, indeed. Yesterday evening there was one fresh flower in bloom with a most sweet fragrance. A little jasmine-like, I thought. Then, this morning, the shrub had many more flowers than it did last night. So, I assume, it blooms at night and it has a sweet fragrance. I’ll have to stay up past my bedtime sometime and look for hawkmoths!
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I just stumbled on this blog and I live in Panama, also. I am a complete ignoramus when it comes to plants, but I am trying to learn. Thank you.
Welcome, Wendy! The more you browse around in this blog, the more you’ll see that I’m a beginner, too. Feel free to leave comments whenever you have questions. Mary