Names
Scientific synonyms (55): Helianthus annuus californicus T.Moore, Helianthus annuus f. fallax B.Boivin, Helianthus annuus f. lenticularis (Douglas ex Lindl.) B.Boivin, Helianthus annuus f. silvester Thell., Helianthus annuus lenticularis (Douglas ex Lindl.) Cockerell, Helianthus annuus mut. inornatus Cockerell, Helianthus annuus subsp. jaegeri (Heiser) Heiser, Helianthus annuus subsp. lenticularis (Douglas ex Lindl.) Cockerell, Helianthus annuus subsp. texanus Heiser, Helianthus annuus var. apicalis Cockerell, Helianthus annuus var. aridus Cockerell, Helianthus annuus var. basalis Cockerell, Helianthus annuus var. californicus (T.Moore) Bushell, Helianthus annuus var. chrysanthemoides Cockerell, Helianthus annuus var. convolutus Cockerell, Helianthus annuus var. coronatus Cockerell, Helianthus annuus var. dilutus Cockerell, Helianthus annuus var. flavobasis Cockerell, Helianthus annuus var. indicus (L.) DC., Helianthus annuus var. latibasis Cockerell, Helianthus annuus var. lenticularis (Douglas ex Lindl.) Steyerm., Helianthus annuus var. macrocarpus (DC.) Cockerell, Helianthus annuus var. niger Cockerell, Helianthus annuus var. pallescens Cockerell, Helianthus annuus var. passiflora Cockerell, Helianthus annuus var. primulinus Cockerell, Helianthus annuus var. pumilus DC., Helianthus annuus var. reversus Cockerell, Helianthus annuus var. revolutus Cockerell, Helianthus annuus var. ruberrimus Cockerell, Helianthus annuus var. selene Cockerell, Helianthus annuus var. semivinosus Cockerell, Helianthus annuus var. texanus (Heiser) Shinners, Helianthus annuus var. tortuosus Cockerell, Helianthus annuus var. trizonatus Cockerell, Helianthus annuus var. vinosissimus Cockerell, Helianthus annuus var. vinosus Cockerell, Helianthus aridus Rydb., Helianthus aridus var. citrinus Cockerell, Helianthus bangladeshinensis Shumon, and more.
In other languages
- en: common sunflower
Where it is recorded
- USDA PLANTS: HEAN3
- GRIN: 27923
- POWO: urn:lsid:ipni.org:names:119003-2
- Wikidata: Q171497
Taxonomy record sources: POWO (CC BY 4.0), USDA_PLANTS_CATALOG (Public Domain). Loaded from the botanica open cultivated-plant knowledge base and the GBIF backbone; each row keeps its origin.
Growth stages
- Initial: about 25 days (FAO 56 Table 11: planted April/May, Medit.; California)
- Crop development: about 35 days (FAO 56 Table 11: planted April/May, Medit.; California)
- Mid-season: about 45 days (FAO 56 Table 11: planted April/May, Medit.; California)
- Late season: about 25 days (FAO 56 Table 11: planted April/May, Medit.; California)
What the sources say it wants
Each line shows the band, then the kind of source and the citation. "Published" means the number is printed on the cited page; "derived" means it was computed from published numbers with the formula recorded on the row; "external API" rows are refreshed nightly from a live source; "curated" rows are OAT's own working values from June 2026.
Initial
| Zone | Measure | Band | Source |
|---|---|---|---|
| Timing | Crop coefficient, initial stage (ratio) | 0.35 | published: FAO Irrigation and Drainage Paper 56, 1998 |
Mid-season
| Zone | Measure | Band | Source |
|---|---|---|---|
| Timing | Crop coefficient, mid-season (ratio) | 1 to 1.15 | published: FAO Irrigation and Drainage Paper 56, 1998 |
Late season
| Zone | Measure | Band | Source |
|---|---|---|---|
| Timing | Crop coefficient, end of season (ratio) | 0.35 | published: FAO Irrigation and Drainage Paper 56, 1998 |
Phenophases observed by the USA National Phenology Network
10 phenophases are tracked for this species and refreshed nightly, as stage triggers: All leaves withered, Flowers or flower buds, Fruits, Initial growth, Leaves, Open flowers, Recent fruit or seed drop, Ripe fruits.
Keystone status
Partial. The KEEP rule asks for a growth stage and a band in each of light, air and root zone before a crop counts as complete; this plant is in the keystone with what its sources give so far.
Generated 2026-09-15 from the OAT plant keystone. Source types and citations are carried on every row; the keystone snapshot that the Library instruments read is plant-targets.json and its quality sheet is plant-targets.quality.json.