Thursday, February 28, 2013
Here’s an easy one. It’s easy because it is very common, and very distinctive.
This is a shrubby species, usually a multi-trunked woody plant, with smooth gray bark, often getting to be a tall shrub, or even a small tree. It is found nearly throughout the eastern United States, from Maine to northern Florida, and generally westward to Texas and Oklahoma. It loves wet soil, and is a common component of floodplain woods and swamps. This species is most often seen on “low” ground, that is, not in high elevations. So, although it is common, you won’t be seeing it in our higher eastern mountains. It’s a flat-lander.
How is it distinctive? Well, it sports attractive, bright green leaves (bright green above and below) which are finely toothed along the edges. The leaf blades are frequently sort of football-shaped, or perhaps a bit egg-shaped...with the wide end of the egg at the tip. These leaves are completely deciduous, and will turn brown in the fall and eventually fall away. Now, this is one of those plants that produces both male flowers and female flowers on the same plant, but separate from each other. (Such a species is said to be “monoecious”...regular old corn would be another good example. Note, however, that trees such as maples, which are either “male” or “female”, are termed “dioecious”.) In our Mystery Plant, the flowers are very tiny and inconspicuous, held together in tight clusters called “catkins” or “aments”. The female flowers develop in small, scaly affairs that look like miniature pine cones. These aments start out somewhat pink, and as they develop, enlarge slightly, becoming hard and woody. Just like a tiny cone.
The male flowers, though, are arranged in more obvious aments that are elongated and wiggly, looking something like long, skinny caterpillars. The scales making up the male ament will each bear three tiny flowers, and these flowers consist only of a few stamens each. VERY small little flowers, but capable, in a mass, of producing quite a lot of pollen. After shedding pollen, these male aments fall away to the ground. Pollen from the male flowers is wind-borne, eventually reaching the females aments, where fertilization occurs. The flowers are easily visible right now, in the earliest part of the spring. After the female aments mature and ripen, their scales will slowly separate, and miniscule, winged fruits will be released. Each fruit contains a tiny little seed. The dried-out female aments remain on the twigs for a good while, but they eventually drop off.
The fact that this plant blooms so early makes it a real treat for botanists, and especially students on a field trip. We saw some of these plants this past week, and I told the students that spring had arrived. I went on and on...and on, I suppose, and then one of the students, busily scribbling notes, said that I sounded like a preacher giving a sermon. How did I respond? “Can somebody give me an AMENT!” (Photo by Tony Adcock.)
Answer: “Tag alder," Alnus serrulata
John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences, Columbia SC 29208. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or call 803-777-8196, or email firstname.lastname@example.org.