Friday, December 4, 2009

Tale of Two Cherries

As you may have seen me post most gleefully on our Facebook page, I have been happily chain-sawing away at the numerous cherry trees in the understory of our forest communities. But what kind of cherries do we have in the Back Woods you might ask? They are two species of cherry both native and common to Florida: Prunus serotina; the black cherry, and Prunus caroliniana; the Carolina laurel cherry. They are in the rose family, Rosaceae, same as roses, plums, and table cherries and yes they too produce an edible cherry. The fruit are produced early to mid spring much to the delight of any fruit eating bird or mammal that comes across them. One of the best sites you will ever see is flock of Cedar Waxwings on their way back north making a stop to strip a Carolina laurel cherry of every last fruit on the tree.

The black cherry is listed as a facultative upland species and you will find it throughout central and northern Florida upland hardwood and pine systems. The Carolina laurel cherry was once popularly cultivated as a common landscape plant and  is now so ubiquitous that whatever natural range it may have had in Florida is no longer known. You will find it in most any condition from wet communities to dry and happy in urban climes. Both species are commonly found along fence rows and in lines under utility lines. Can you you think why?

In the growing season many people find it hard to tell these two trees apart without a closer look. Although the Carolina laurel cherry is a smaller tree and evergreen it can be easily confused with small black cherry in the understory. As the winter approaches and the deciduous black cherry begins to lose their leaves, it is a little easier to tell the two apart with a cursory glance.  Below are a few key field characteristics you can use to tell them apart in the field any time of year.

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Strong transverse lenticels (lenticels are corky tissues that grow around pore like structures allowing for the exchange of air through the bark) mark the bark of the black cherry while the Carolina laurel cherry's bark appears smoother until greater maturity (but there are lenticels there too.)

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A cursory glance at the leaves  in the growing season and the two cherries can be easily confused. A closer look reveals some easily distinguishable differences. The first thing I usually do is pluck a leaf off and crush it thoroughly in my fingers and smell the remains. The Carolina laurel cherry typically has a distinct strong scent of almonds (think taking a big sniff of a jar of maraschino cherries and you have got it) from the release of (yes) cyanide in the plant tissues. The black cherry has a more non descript maybe burnt green, if there is such a thing, smell to the foliage but, is also supposed to have a cherry like smell to the twigs and wood. A closer look at the leaves reveals fairly widely spaced sharp pointed teeth along the margin of the Carolina laurel cherry whereas the the black cherry has many smaller appressed teeth along the margin.

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Black cherries have, in comparison, longer petioles than Carolina laurel cherry and are notably grooved down the center. The Carolina laurel cherry petiole is most often blush in color like the photo above. A key distinction between the two are the little knobby glands found on the petiole near the base of the leaf blade on the black cherry. But as with most physiological identifying characteristics, there is always variability. Note the photo below of three black cherry leaves. The first doesn’t have any notable glands, the second is adorned with two perfectly placed glands, and the third has a potential little knobby projection in one spot at the base of the leaf. Look at several leaves and go with the general trend to make your decision which plant is which.


And to answer the question of why we would be removing these trees from the forest… Both species make up a shade tolerant sub canopy under the oak and pine in our  fire suppressed plant communities. We are removing this secondary canopy of trees and some of the oak over story to restructure the forest back to an open longleaf pine canopy forest. The classic longleaf pine flatwoods and sandhills have a sparse canopy of towering longleaf pines with a mixture of shrub or grasses as an understory depending on how frequently the community is subjected to fire. Both cherries, which are important to wildlife, will still be contributing species to the composition of the plant communities but will no longer dominate the under story. This will allow for a more diverse suite of plants and animals to inhabit the Back Woods.

Check the Virginia Tech Tree ID site or the Duke University site on Trees Shrubs and Vines of North Carolina for some nice additional id  sheets on our two cherries with nice pictures of the flowers and fruit and more great bark examples.

1 comment:

Anonymous said...

Thank you. I've been wondering what we had in the yard. The chickens seem to like the berries but can we humans eat them too?