Rudbeckia hirta

In the wild in the US, this plant grows in prairies, pastures, and cultivated fields, where it is considered a weed. Except in Maryland, where it is the state flower.

The genus name honors Olof Rudbeck (1630-1702) Swedish botanist and founder of the Uppsala Botanic Garden in Sweden where Carl Linnaeus was once a professor of botany.

The species name of hirta means “hairy”, a reference to the short bristles that cover the leaves and stems.

It is toxic when ingested by cats, but was used medicinally by Native Americans.

🎨 All Rudbeckia species are dye plants (especially R. hirta and R. laciniata) due to the presence of flavonols in their tissues. The inflorescences alone produce yellow-orange colors, while the entire plant gives yellow-green hues.

🌸 Floral Morphology : Rudbeckia hirta

The plant itself is a herbaceous perennial, though in many climates it behaves like a short-lived perennial or even an annual.

Its stems are hairy and upright, supporting the flower heads in a way that maximizes visibility to pollinators, while its rough, lance-shaped leaves are adapted to conserve moisture and deter herbivory.

The floral collar is divided into two concentric zones of different colors, a bright yellow border surrounding a central orange-yellow zone.

Interestingly, the hairs on the leaves and stems can also reflect light, slightly reducing leaf temperature and helping the plant survive in open, sunny prairies.

🌱 Reproductive Biology

From a reproductive standpoint, Rudbeckia hirta is prolific. The plant produces small, dry fruits called achenes, which often self-seed around the parent plant.

This self-seeding habit, combined with its long blooming period from mid-summer to early fall, makes ‘Prairie Sun’ particularly resilient in gardens and wildflower plantings.

Its bright yellow flowers are highly attractive to bees, butterflies, and even some birds, highlighting its ecological role beyond simple ornamentation.

🌍 Ecology & Adaptations

Native to the prairies and open fields of North America, where it thrives in well-drained soils, including dry, sandy, or rocky sites.

It prefers full sun and tolerates moderate drought, although heavy or waterlogged soils are less suitable.

Although it is a short-lived perennial, typically lasting one to two years, it readily self-seeds, allowing it to persist in gardens and wildflower meadows.

Its bright flowers, which bloom from midsummer through early autumn, attract a wide variety of pollinators, including bees and butterflies, while its seeds provide food for birds and small mammals.

Naturalized in Europe, Rudbeckia hirta grows easily in temperate climates without becoming invasive, making it a common feature in dry gardens, roadside verges, and meadow plantings. B

y providing extended nectar and pollen resources, supporting wildlife, and improving soil structure with its fibrous roots, it contributes significantly to local biodiversity and ecological resilience.

Other Names:

Black eyed Susan

Yellow coneflower

Origin:

North America