The Asteraceae (sunflower) family contains the largest number of species world-wide. Thus, it is often broken down into tribes or sub-families in order to make more sense of it. The genus Solidago contains the goldenrods for which there are about 100 species worldwide and 25+ species occurring in Louisiana alone. These plants are a prominent feature of the fall landscape across eastern North America. Goldenrods are characterized by rows of tiny yellow disk flowers atop a green, leafy, and upright stem. Distinguishing between different species of goldenrods can be very difficult, even to a trained botanist. Thus, curated herbarium specimens are highly valuable for comparative studies.
The Director of the Shirley C. Tucker Herbarium at Louisiana State University, Lowell Urbatsch, has been working with a goldenrod specialist in Canada, John Semple, who recently discovered two species never recorded in Louisiana, namely Solidago brachyphylla and S. rigidiuscula, indicating that there is still a lot to learn about this important genus.
Goldenrods are often blamed for fall allergies when they become prominent in fields and roadsides. However, this is not likely the case since the pollen is not airborne. Instead goldenrod pollen is carried by a plethora of insects that favor visiting these bright yellow flowers. Another member of the sunflower family, ragweed, blooms at the same time and in similar habitats, is far more likely the culprit of seasonal sniffles.
Louisiana State University will be hosting a WeDigBio event this weekend focused on transcription of this important genus.