“What’s the best way to recognize a dogwood? By its bark.”
Haw, haw... I love that old joke and so do my students.
Seems like a couple of weeks ago, this column featured an oddball tree, featuring thorny stems and which produces a soft, edible, reddish fruit that is at least marginally palatable. Of course, that was a “strawberry tree,” or Cudrania tricuspidata, a member of the mulberry family.
This week we have a different small tree — without stickers — that also produces a soft, red, mushy fruit, but the two plants are not at all related. And sure enough, this week’s mystery plant is indeed a kind of dogwood.
All the dogwoods of the world belong to the genus Cornus and there must be something like 60 different species. Most are woody, either shrubs or trees, but a few are actually herbaceous, or nearly so, not getting very high off the ground.
There is a lot of controversy among botanists as to the relationships of these numerous species. After all, the forms of the flowers and fruits vary considerably within the various subgroups of the genus.
Some species have bright red one-seeded fruits like a familiar flowering dogwood, but others have similarly shaped fruits that are a beautiful gun-metal blue such as swamp dogwood.
Then there is this very curious species. Its leaves are not much different from those you’ll see on the common, spring-blooming dogwood of our Southern yards and streets; the one named Cornus florida, and unfortunately, a species now prone to a serious anthracnose disease.
The mystery tree also has large, conspicuous white bracts (four, five, or sometimes six) surrounding the inconspicuous flowers, produced in the summer, not the spring.
I hate to disappoint some of you here, but those four white “petals” on our familiar eastern dogwood are actually modified leaves, or bracts. That’s right: next spring, check out the “flower” of the dogwood in your yard, and you will see that there are four white leaf like bracts surrounding a cluster of small, yellow-green blossoms.
On the common flowering dogwood, the fruit is a shiny, single-seeded “drupe”... cherished by the mockingbirds, cardinals and squirrels late in the winter.
With the mystery plant, the fruits are spherical and bumpy, maturing juicily into a kind of gooshy, swollen, red berry a good two inches across... which some people like to eat.
The mystery species is a beautiful small tree, suitable for Southern gardens.
It is actually a native of eastern Asia, and interestingly, seems to be related, based on flower and fruit characters, and according to DNA evidence, to a very similar species, which grows on the Pacific coast from southern California to British Columbia called “Pacific dogwood.” If you happen to have one of these trees in your yard, it has probably dropped just about every one of its leaves by now.
The leafy branch and fruits seen in the picture were sent to us for identification. If you have plants that you’d like identified, please contact us.
John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences. As a public service, the herbarium offers free plant identifications. For more information, visit www.herbarium.org, call 803-777-8196 or email nelson@sc.edu.
Answer: “Kousa dogwood,” Cornus kousa.