Regularity: Regularly occurring
Global Range: Utah and northern Arizona (46,000 sq. km.) on the Colorado Plateau with extension to the eastern Great Basin into Nevada.
Catalog Number: US 1487743
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): W. Stanton
Year Collected: 1930
Locality: Desert S of Hawksville., Wayne, Utah, United States, North America
- Holotype: Blake, S. F. 1931. J. Wash. Acad. Sci. 21: 333.
Comments: Sand dunes and swales between 1,200 and 2,000 m. elev.; under sand dune agriculture in southern part of its range.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: Monument Valley and Hopi Ind. Res. in Navajo Co., Beaver Dam in Mohave Co., Arizona; ten counties in Utah.
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: Colorado Plateau and Great Basin, widespread, but often in low numbers at particular sites.
Comments: Modernization and mechanization of agricultural practices; total abandonment of agricultural fields; road construction.
Biological Research Needs: Habitat requirements and population biology; overcome difficulties in germinating wild seed.
Helianthus anomalus, Western sunflower, is a plant found in the southwest region of the United States. It is of particular interest due to its genetics. It was produced via hybridization of two other sunflower species, H. annuus and H. petiolaris, multiple times between approximately 60,000 and 200,000 years ago. From these two parent plants, three hybrids were formed, each with distinct characteristics and habitat preferences.
Helianthus anomalus is found in the United States in Arizona, New Mexico, Nevada and Utah. Both H. anomalus hybrids are subject to stressful ecological conditions. They grow in sand dune habitats, which have limited access to nitrogen and water, and are thus considered stressful environments. H. anomalus is native to these states, not introduced.
Habitat and ecology
Helianthus anomalus has unique traits that allows it to thrive in its stressful sand dune environment. H. anomalus has a high leaf succulence, which allows it to survive long periods of drought common to its habitat. The succulent leaves of the sunflower stores water in absorbent, spongy portions of the leaves. H. anomalus also has large seeds and rapid root growth, which contribute to its ability to survive in its extreme environment. It is believed that large seeds are adaptive to dune plants because the large seed size prevents burial by the sand. H. anomalus is an annual plant.
Morphology, flowers and fruit
Individuals of this species can be recognized by their yellow flowers, with alternate oval shaped leaves. H. anomalus produces achenes for fruits. A 2001 study done on multiple species of Helianthus showed the average height of the plant to be 1.2m, with an average leaf length of 9.69 cm. Their average root length of 6.45 cm is an adaptation to their dry environment; they have to be able to acquire water from deep within the soil. The large size of their achenes facilitates this expanding root growth.
H. anomalus is of particular interest to biologists because it is a natural hybrid, meaning the species originated in nature from a hybridization of two other sunflowers. The parental flowers, H. annuus and H.petiolaris, are found in dramatically different environments. H annuus is found in clay based soils while H. petiolaris is found in sandier soils. The hybrid flower, H. anomalus, is able to inhabit such a different and stressful environment due to divergence in parental gene dominance. Common garden experiments of the parental and hybrid flowers show distinct preference to their different habitats.
Applications in biotechnology
H. anomalus has been considered a potential source of alternate fuel. The need for alternate fuel sources has been a pressing issue over the past ten years, and sunflower oil is one of the possible candidates. Among the 51 species of the Helianthus genus, H. anomalus shows promise because of its high oil concentration, linoleic fatty acid concentration and its large achenes.
- Gurevitch, Scheiner and Fox (2006). The Ecology of Plants. Sunderland, MA: Sinauer Associates. pp. 151–152. ISBN 978-0-87893-294-8.
- "Helianthus anomalus S.F. Blake. Western sunflower". United States Dept. of Agriculture. Retrieved 4 May 2014.
- Ludwig, Rosenthal and Donovan; Rosenthal, D. M.; Johnston, J. A.; Kane, N; Gross, B. L.; Lexer, C; Dudley, S. A.; Rieseberg, L. H.; Donovan, L. A. (December 2004). "Selection on Leaf Ecophysiological Traits in a Desert Hybrid Helianthus Species and Early-Generation Hybrids". Evolution 58 (12): 2682–2692. PMC 2562700. PMID 15696747.
- Seilier, Gerald J. "Wild Helianthus anomalus and H. deserticola from the Desert Southwest USA: a Potential Source of Stress Genes for Cultivated Sunflower". 4th International Crop Science Congress. Retrieved 4 May 2014.
- Schwarzbach, Donovan and Rieseberg; Donovan, L. A.; Rieseberg, L. H. (February 2001). "Transgressive character expression in a hybrid sunflower species". American Journal of Botany 88 (2): 270–277. PMID 11222249. Retrieved 4 May 2014.
- Noor, M.A; et al. (2006). "Evolutionary genetics: jumping into a new species.". Current Biology 16: 890–892. Retrieved 4 May 2014.
- Seiler, G.J. (January 2011). "Wild annual Helianthus anomalus and H. deserticola improving oil content and quality in sunflower". Industrial Crops and Products 25 (1): 95–100. Retrieved 4 May 2014.
Names and Taxonomy
Comments: Considered a distinct species from Helianthus deserticola by Kartesz in the 1994 checklist, but his 1999 floristic synthesis includes H. deserticola in H. anomalus. Utah Heritage Program also treats H. anomalus more broadly, including H. deserticola in their concept of H. anomalus. Per Jim Morefield, molecular studies indicate that the two taxa are distinct, but per Cronquist (1994) they are not otherwise distinguishable.
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