Helianthella quinquenervis (Asteraceae)
Helianthella quinquenervis is commonly known as the Aspen sunflower, though it is referred to by other common names such as the nodding sunflower and the little sunflower. Because each leaf has five prominent veins, H. quinquenervis is also called the Five-Nerved or Five-Veined Sunflower. Helianthella quinquenervis is just one of eight herbaceous perennial sunflower species in the genus Helianthella.
H. quinquenervis occupies mountainous regions in many habitats (aspen, lodgepole pine and ponderosa pine forests as well as open meadows, wetlands and bogs). Specimens have been collected throughout the western United States, including AZ, CO, ID, MT, NM, NV, OR, SD, UT and WY. Its range extends south to Chihuahua and Nuevo Leon, Mexico.
Before flowering begins, the Aspen sunflower begins to secrete extrafloral nectar, which is rich in sugar and amino acids. Since the plant has no natural chemical or physical defenses, the nectar attracts ants including some species from the genus Formica, to protect flower heads from pre-dispersal seed predation. Male and female tephritid flies meet on H. quinquenervis for courtship and mating. The female lays her eggs between the bracts of the unopened flower head. When the eggs hatch, the fly larvae feed on the seeds. The ants collect the nectar produced by H. quinquenervis and patrol the stalks while they are waiting for more nectar to be secreted. When an ant encounters tephritid flies mating or laying eggs, the ant will charge the flies, causing them to leave. Seed loss decreases significantly when ants are present among Aspen sunflowers.
Note: The two most common species of tephritid flies on Helianthella around Gothic are Neotephritis finalis and Trupanea nigricornis.
Highlighted RMBL Research
de Valpine, P. and J. Harte. 2001. Plant responses to experimental warming in a montane meadow. Ecology (82) 637-648.
Inouye, D. W. 2006. Demographic consequences of climate change for a montane sunflower (Helianthella quinquenervis): Frost effects on population size and size structure. Consortium for Integrated Climate Research in Western Mountains, MtnClim 2006, Mount Hood, OR.
Inouye, D. W. 2008. Effects of climate change on phenology, frost damage, and floral abundance of montane wildflowers. Ecology (89) 353-362.
Inouye, D. W. and R. S. Inouye. 1980. The amino acids of extrafloral nectar from Helianthella quinquenervis (Asteraceae). American Journal of Botany (67) 1394-1396.
Inouye, D. W., O. R. Taylor (1979) A Temperate Region Plant-Ant-Seed Predator System: Consequences of Extra Floral Nectar Secretion by Helianthella quinquenervis. Ecology (60) 1-7.
Encyclopedia of Life
Learn more about Helianthella quinquenervis at the Encyclopedia of Life.
Many thanks to Mary Goodwin and Dr. Pat Magee at Western State College for this submission, and to RMBL Researcher Dr. David Inouye of the University of Maryland for his review and additions.