Sandra asked what they were called, but I have never known the name. Mark brought me two packets of wildflower seeds from the Denver airport several years ago, and this is one of the plants that grew from the seed. So I just did a little detective work and found a wonderful site for identifying wildflowers: http://www.wildflowerinformation.org/
I think I'll be using this site often!! Thanks for asking, Sandra!!
Yellow Prairie Coneflower
Ratibida columnaris (yellow)
About Yellow Prairie Coneflower (Ratibida columnaris (yellow))
Height: Up to 3 ft.
Flower Color: Yellow
Plant Type: Perennial. Returns each spring from same roots, forming expanding clump. Blooms second spring from seed.
Flower Type: Daisy-like
Bloom Time: Mid-season
Is this wildflower invasive? No
Is this wildflower endangered? No
Is this wildflower edible? No
Is this wildflower medicinal? No
What is Yellow Prairie Coneflower's native range?
Indigenous To: From western Canada into Mexico.
Where Yellow Prairie Coneflower is naturalized or can be grown
Regions: Native to plains regions, but can be grown in all regions.
How to grow Yellow Prairie Coneflower (Ratibida columnaris (yellow))
Soil preference: Somewhat adaptable, but prefers non-acid, dry conditions
Sun/Shade: Needs full sun.
Moisture Requirements: Adaptable to even arid conditions.
Like all desert or arid area wildflowers, ratibidas need loose, gritty soil to do well. Given these conditions, they perform as classic perennials, and are easy to grow.