Rudbeckia grandiflora

tall coneflower, rough coneflower, plantainleaf coneflower
Family

Asteraceae

Leaf Arrangement

alternate

Leaf Attachment

petiolate

Leaf Type

simple

Leaf Shape

elliptic, lanceolate, ovate

Growth Form

forb, shrub

Flower Color

yellow

Flower Petals

many

Flower Month

April - October

Height (meters)

0.5 - 1.5

Milky Sap

No

Armed/Unarmed

Unarmed

Origin

native

Lifespan

perennial

Growing Season

Warm season


Prairie Coefficient of Conservatism

8

Field Characters

Similar to R. maxima which has leaves up to 15 cm wide with a whitish, waxy coating and disk flowers 8 cm long, while the leaves of R. grandiflora are less than 8 cm wide, lustrous, and its disk flowers are less than 6 cm long. It is also similar to R. texana which has disk flowers that are 4-8 cm long in fruit and lower leaves 16-25 cm long by 6-8 cm wide, often triple nerved below, while R. grandiflora has disk flowers that are less than 4 cm long in fruit and basal leaves that are 8-15 cm long by 5-10 cm wide and 5- to 3-nerved. Stem and leaves not hairy, style branches short and blunt. Achene with 4 nearly equal facets.

Cultural Information

Easily grown from seeds collected in the fall when the cones become loose. Seeds germinate with no treatment in 1-2 weeks. Steffen (1997) recommends cold/moist or cold/dry stratification, possiably to break dormancy induced by long term storage. Plants

Animal Use

The leaves are eaten by white-tailed deer (Holmes 1990) Cattle occasionally graze early leaves. Quail and doves feed on the seeds.

Natural History

The Acadian name for all of the yellow coneflowers is "marguerite" (Holmes 1990).

Habitat

Open dry woods and prairies.