Helianthus anomalus
western sunflower
Family Asteraceae
About
Western sunflower is an annual sunflower of sand dunes in the southwestern United States. It arose in the wild from crosses between the common sunflower and the prairie sunflower, and is assessed as Vulnerable.
Care at a glance
- Pet safety
- Not recorded. We have no source on whether this plant is safe for cats, dogs or other pets — that is not the same as safe. Keep it out of reach until you have checked.
- People
- Not recorded.
- Light
- Full sun gives the most flowers; partial shade is tolerated. General guidance for the genus
- Mature size
- Averages about 1.2 m tall.
“General guidance for the genus” marks advice sourced for the genus as a whole rather than this species.
Field notes
Morphology
An annual with yellow flower heads and alternate, oval leaves that are notably fleshy. The fruits are large achenes. In one study plants averaged about 1.2 m tall, with leaves about 10 cm long.
Distribution & habitat
Native to Arizona, New Mexico, Nevada and Utah, where it grows on sand dunes that are low in nitrogen and water.
Ecology
Built for shifting dunes: succulent leaves store water through long droughts, and large seeds with fast-growing roots are thought to keep seedlings from being buried by sand and help them reach deeper moisture.
History & etymology
Studied as a classic case of hybrid speciation: it formed several times from natural crosses of H. annuus and H. petiolaris, roughly 60,000–200,000 years ago, and colonised a harsher habitat than either parent. Its oily, large achenes have been examined as a possible biofuel source.
Conservation
Assessed as Vulnerable and declining in its native range.
Habitat
- Altitude
- Not recorded
- Altitude class
- —
- Native to
- United States
- IUCN status
- Vulnerable
Cultivation
- Difficulty
- Not recorded
Text adapted from Wikipedia, CC BY-SA 4.0.
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