Western Sunflower OR''

Western Sunflower OR''

Western Sunflower

The Western Sunflower is one of the more unique sunflowers belonging to the Helianthus genus. In the botanical world, the Western Sunflower is known as Helianthus occidentalis. Western Sunflower is easy to identify, the basal leaves form a rosette structure and the stem of the plant shoots up from the middle of it. Western Sunflower grows lankily up to 3 feet tall, where the brilliant yellow flower head blooms. Helianthus occidentalis can be easily identified through its lack of leaves all the way up the stalk. This is how it has earned nicknames such as “naked stemmed sunflower” or “few leaved sunflower”.


Like many Helianthus species, the Western Sunflower prefers to grow in drier soils where it can receive full to partial sun. Western Sunflower does well in the sandiest of soils and is generally found in upland prairies. This species follows another common trait of Helianthus plants seeing as it is rhizomatous and will spread via its roots. However, it is one of the less aggressive sunflower species. Western Sunflower is frequently visited by pollinator friends including bees, flies, and the intermittent butterfly. Many insects feed on its foliage and use the stems to burrow inside. It is also common for passing by birds, such as Doves and Goldfinches, to feed on the seeds.Faunal Associations: The pollinators of Western Sunflower are probably similar to those of other sunflowers that grow in relatively open areas. This includes such insects and long-tongued bees, short-tongued bees, miscellaneous flies, and occasional butterflies. The following bees are oligoleges (specialist pollinators) of sunflowers (Helianthus spp.): Dufourea marginata, Andrena accepta, Andrena helianthi, Andrena aliciae, Melissodes agilis, and Pseudopanurgus rugosus.

Other insects feed on the foliage, bore through the stems, feed on the florets and seeds, or suck plant juices from sunflowers. These species include: the leafhoppers Mesamia straminea and Mesamia nigridorsum, the aphids Uroleucon illini and Uroleucon helianthicola, the plant bugs Ilnacora stalii and Ilnacora malina, Haplorhynchites aeneus (Sunflower Head-Clipping Weevil) and Cylindrocopturus adspersus (Sunflower Stem Weevil), the leaf beetles Physonota helianthi and Trirhabda adela, Contarinia schulzi (Sunflower Midge) and Neotephritis finalis (Sunflower Seed Maggot), Melanoplus packardii (Packard's Grasshopper) and Sparagemon collare (Mottled Sand Grasshopper), and the flower thrips Heterothrips auranticornis (see Insect Table for a more complete listing of these species). In addition to these insects, the larvae of such butterflies as Chlosyne gorgone (Gorgone Checkerspot), Chlosyne nycteis (Silvery Checkerspot), and Vanessa cardui (Painted Lady) feed on sunflowers, as do the larvae of Papaipema necopina (Sunflower Borer Moth), Suleima helianthana (Sunflower Bud Moth), and other moths. (Source:www.illinoiswildflowers.info)



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