Last February for a couple of weeks or so it seemed we were surrounded by plants bearing small white flowers with many stamens (male reproductive parts). Most of those plants are producing fruits now, and it turns out two of them, at least, are very closely related. First the flowers:
The flower on the left has tannish anthers (pollen sacs) at the tips of the stamens and pink tinges at the base of the petals. If you click on the image to enlarge it, you should be able to see a greenish pistil (female reproductive part) near the middle of all the stamens.
The flower on the right has white anthers, all-white petals, and a white pistil.
Now for the berries:
The red berry on the left is the first fruit of the young cereza (Spanish for “cherry”) plant in our orchard, which we purchased from MIDA, the Panamanian government source for saplings and young plants. The green, maroon, and blue berries on the right are berries from the escobillo (Spanish for “broom” or, literally, “I sweep”) shrub growing on a volunteer, untended shrub in our yard. Below are the respective plants when they were in bloom.
Both these plants, the cultivated plant and the volunteer shrub, belong to the same genus of the family Myrtaceae. You might guess from the similarity of the flowers that they belong to the same family, but what makes them members of the Myrtaceae family in particular?
The Myrtaceae (Myrtle) Family
The family gets its name from the Myrtle genus, Myrtus, which is native to Europe and north Africa. A member of that genus, the common Myrtle, Myrtus communis, is said to have been sacred to Aphrodite and Demeter (wikipedia), but I haven’t been able to find out why.
Members of the myrtle family are woody with essential oils. They include: myrtle, clove, guava, feijoa, allspice, and eucalyptus (wikipedia). There are at least 3,000 species in the family and 130-150 genera.
To recognize a member of the Myrtaceae, Gentry (one of my favorite plant ID books for this area) says we need know only three characteristics of the leaves, at least for the Myrtaceae in our area.
The leaves are
- pellucid-punctate (dotted with translucent pits)
Here are those characteristics in our two plants:
On the left is a stem from the plant in the orchard, showing simple leaves coming off opposite sides of the stem. On the right is a stem from the shrub, same thing. The shape of the leaves is quite different, but the arrangement of the leaves of each is opposite and the type of the leaves is simple (not compound – for more details on this distinction see here).
Those translucent pits can be seen pretty easily in the orchard plant. There’s a red rectangle in the left image (you can see it better by clicking on the image to enlarge it). The right image is a magnification the leaf section within that rectangle.
The pits in the leaves of the shrub are not so easily seen without magnification, so I scanned one for a better view. To have a comparison, I also scanned a leaf from the orchard plant. Again, the orchard plant is on the left, the shrub on the right. You can see the pits better in both cases in the enlargement.
So we have clear evidence that these plants belong to the Myrtaceae family – opposite, simple leaves with translucent pits.
The genus is harder to pinpoint. Gentry points out that although the family is very easy to recognize by the combination of the above characteristics, determining the genus is especially difficult in the Myrtaceae family. As frequently happens with me, I stumbled on the scientific name of one of these plants by accident, and the other followed as night by day. I was browsing through the wonderful book by Carrasquilla when I saw a picture of the broom plant…Eugenia biflora.
The Eugenia Genus
The genus was named by Linneaus himself – for Prince Eugene of Savoy (1663-1736), an Austrian general (Dave’s botanary) known for his patronage of the arts (Columbia Encyclopedia). Don’t ask me why Linneaus decided to honor the prince in this way!
Eugenia is found mostly in the New World. Like other members of the Myrtaceae, the sepals, which lie beneath the petals, stay on the plant after the petals fall off. Here are the sepals of the shrub, which I find quite attractive:
One of the distinguishing features of Eugenia species is that their flowers and fruits are carried on pedicels, or stalks. And here is where we come to the very close similarity of these two plants.
The scientific name of the plant from the orchard, the one with tannish anthers and pink tinges at the base of some of the petals, is Eugenia uniflora – which means single-flowered.
The scientific name of the plant from the yard, the all-white flower, is Eugenia biflora – which means with two flowers.
Here’s why (click on each image to enlarge):
The flower pedicel (arrow) for Eugenia uniflora, on the left, supports only one flower. The flower pedicel (arrow) for Eugenia biflora supports two flowers, more easily seen in the image after the petals have fallen away and only the sepals remain.
Very closely related, indeed!
The fruit of Eugenia uniflora is also known as the Suriname Cherry or the Brazilian Cherry. I missed getting a good picture of the fruit from our first-year plant, but A. V. Popovkin at Flickr has a great one, used here with his kind permission:
You can see that the fruit is 8-lobed, like a little pumpkin. It’s high in vitamin C and when very ripe has a sweet taste which can be resinous. Here in Panama it’s simply called cereza and it is prized for eating as is and for jams.
Because it is valued as a fruit and an ornamental plant, E. uniflora has been distributed to places in the world well beyond its native Brazil and the Neotropics, as shown in this map from the Global Biodiversity Information Facility (GBIF).
The fruit of E. biflora is edible, but I don’t know that many people here take advantage of it. It’s pretty small and has a big seed, and so may not be worth the effort.
This plant has not been distributed as widely as E. uniflora. It is confined to the West Indies and Central and South America.
Here in Panama, the leaves and branches are put to good use in some areas as brooms, and, as mentioned, the common name for the plant is escobillo, meaning “I sweep.” I remember a day in early January a couple of years ago while waiting for our weed-eater to be repaired visiting with the wife of the mechanic. She told me that it was a New Year’s custom to make a new broom for the house.
She promptly went out into her yard, cut some branches from from an escobillo shrub, lashed them to a pole, and handed me my New Year’s broom. It worked, too!