Native Species Profiles - Three Rudbeckias are better than one

Many people are familiar with at least one plant in the Rudbeckia genus.  Cultivars of the Black-eyed Susan (Rudbeckia hirta) are among the most popular garden flowers.  They bloom profusely and for a very long time.  I have several clumps of them in my garden at home.  They also grow wild throughout Michigan (and just about every other state and province in North America - 47 states and 10 provinces).  It grows easily in sunny habitats like prairies, fields, and roadsides.  It also does well in the light shade of open woodlands.  It tolerates a range of soil conditions from mesic to dry - the plant does wilt easily in dry conditions.

With their dark brown central disk and yellow rays, if there is one common wildflower that the majority of people could probably recognize it's the Black-eyed Susan.

Rudbeckia hirta

Black-eyed Susan in a meadow habitat

Basic Information


Black-eyed Susan 
Rudbeckia hirta

Height:  1-3’ tall

Habitat:  prairies, fields, open deciduous woods

Flower Color:  yellow with brown center
   
Bloom Time:  July – September

Black-eyed Susans are not the only Rudbeckia species that can be found in Mid-Michigan. The Thin-leaved Coneflower (Rudbeckia triloba) is found in the same types of dry habitats as R. hirta.  I find it to be more common in shaded habitats than the Black-eyed Susan.  Its overall range is considerably smaller than that of the Black-eyed Susan.  It can be found in east of a extending from Ontario southwest to Texas, with two small populations in Colorado and Utah

Also known as the Brown-eyed Susan, R. triloba also has brown disk flowers surround by yellow rays.  However, the flowers of the Thin-leaved Coneflower are smaller (1.5-2.0 inches across) and more numerous than than those of the Black-eyed Susan (2.0-3.0 inches across). 

Rudbeckia triloba

Basic Information


Thin-leaved Coneflower 
Rudbeckia triloba

Height:  2-5’ tall

Habitat:  fields, prairies, thickets, open woods, roadsides

Flower Color:  yellow w/ brown center

Bloom Time:  June – October


A third species of Rudbeckia that is common across Michigan is the Cut-leaved Coneflower (Rudbeckia lanciniata).  Also known as the Tall Coneflower, this species can reach heights of 3 to 12 feet.  Unlike the R. hirta and R. triloba, the Cut-leaved Coneflower prefers wet habitats such as floodplains, wet woodlands, and swamps.  Its range is similar to that of the Black-eyed Susan, being found in 45 states and 8 Canadian provinces.  Like most other Rudbeckia species the Cut-leaved Coneflower blooms consist of yellow rays surrounding a central disk - the disk flowers are yellowish green.  Each bloom can be 3 to 4 inches across.  The rays on the Cut-leaved Coneflower tend to droop more than those of other Rudbeckia species.

Bee on Cut-leaved Coneflower

Rudbeckia lanciniata

Cut-leaved Coneflower in a Cedar Swamp

 
Basic Information

Cut-leaved Coneflower
Rudbeckia lanciniata

Height:  3-12’ tall

Habitat:  wet woodlands, swamps, shrub swamps, floodplains

Flower Color:  yellow

Bloom Time:  July – October


Two other species of Rudbeckia have been recorded in Michigan: R. fulgida (Showy Coneflower) and R. subtomentosa (Sweet Coneflower).  R. Fulgida can be found in wet habitats across the southern third of Michigan.  A single record of R. Subtomentosa was recorded in Gratiot County in 1894.