Are you sneezing? Don’t blame those yellow-flowering beneficials
I call it “the yellow season.” In California, springtime brought a golden layer of pine pollen that I swept off my windshield daily. When I moved to New Mexico, I associated pollen allergies with the profusion of shrubs covered in bright yellow as fall approached.
I’m not sure why we often associate our allergy symptoms with yellow. In color psychology, yellow is described as the brightest color in the spectrum and the one most easily discerned by humans. So it appears we arewired to see yellowfirst.
Goldenrod is the assumed villain for hay-fever misery in the East. But according to Andrea DeLong-Amaya, director of horticulture at the Lady Bird Johnson Wildflower Center at the University of Texas Austin, “The real culprit is ragweed.” Ragweed blooms simultaneously, but “people don’t see those flowers, which are green or white, small and not showy,” while the brilliant yellow flowers of goldenrod are highly visible.
At this time of year in New Mexico, it’s chamisa (Chrysothamnus nauseous, also known as rabbitbrush)that provides so much vivid yellow in the landscape. Yet in the daily pollen reports of local newspapers, chamisa (also known as rabbitbrush, chamiso, or rubber rabbitbrush) is not mentioned. We get pollen counts for chenopods, part of the amaranth plant family, which includes such weeds as pigweed and goosefoot; as well as the common food plants spinach and quinoa. Counts are also given for grasses, sagebrush, and ragweed. But there is no mention of chamisa either by its botanical name, Ericamerica nauseosa (formerly Chrysothamnus nauseosus) or its plant family, Asteraceae.
According to the website pollen.com, “This genus is not commonly cited as a source of allergy.” They rate the chamisa’s allergenicity as “mild.” So are we once again opting to accuse the “yellow” plant when there are more prolific pollen-producers surrounding us?
DeLong-Amaya points out that pollen has to be inhaled to cause allergy symptoms. If a plant depends on airborne pollination, it will produce massive quantities of light pollen in order to assure that some of it gets to the right plant. But the pollen of plants that depend on insect pollination is heavier or stickier so that insects are better able to carry it from plant to plant. Therefore, insect-pollinated plants don’t need to produce as much pollen in order to get it to the right plant. In her example, the maligned goldenrod has heavy pollen, while ragweed has light pollen.
In addition to ragweed producing airborne pollen in our area, what about those grasses, chenopods, and sagebrush? On the website Sciencing, Henri Bauholz points out that flowers of wind-pollinated plants don’t need to attract much attention so are often dull or inconspicuous. “Wind-pollinated grasses tend to produce large amounts of pollen, which can cause allergy problems in people,” he writes. Ragweed’s allergenicity on pollen.com is rated as “severe.” Andwhile sagebrush and chamisa are in the same family, often growing side by side, it is the sagebrush that gets a “severe” rating for allergies.
Chamisa is a native plant with tremendous value to our native pollinators. David Salman ofWaterwise Gardening in Santa Fe, claims, “Rabbitbrush is an invaluable source of nectar and pollen for feeding the bees in autumn.” The flower heads are a cluster of tubular flowers. In a TaosNews article, Steve Tapia observed that the “bright yellow blossoms attract numerous bees, wasps, butterflies and other pollinating insects at a time when few other nectar and pollen sources are available.” So from now on, when I ponder the various plants surrounding us in the fall, I’ll remember that there are many sources of pollen and perhaps chamisa is the least troublesome to humans and one of the most valuable to our regional ecosystem.
Laurie McGrath has been a certified Master Gardener in Santa Fe County for 18 years and is a founding member of the Santa Fe Native Plant Project (SNaPP), an advanced Master Gardener training with the goal of educating the public about the many benefits of using native plants in the home landscape.
Painted lady butterfly sipping nectar from chamisa flowers; courtesy U.S. Department of the Interior, Bureau of Land Management