Sunday, June 17, 2012

Rudbeckia Returns

The flowers of the genus Rudbeckia are beginning to flower in my garden and along the roadsides.  Rudbeckia flowers are known generally as “black-eyed Susan” or “coneflower”. The latter name can lead to some confusion because flowers in the Echinacea genus and the Ratibida genus are also commonly known as coneflowers. But Rudbeckia is always a cheery yellow so we at least have that consistency!

Rudbeckia hirta

The one that I have which flowers the earliest is the oft-used (and well-loved) Rudbeckia hirta, or black-eyed Susan. The leaves and stems of this particular species are quite hairy; the species epithet “hirta” is one of many epithets that indicate that the plant has noticeable hairs (hirtum, hirtifolia, hirtissima , hirtifolius , hirsute, hirsuta, hirsutum, hirsutus, hirsutissima – there are more!). 

Listed as an annual, a biennial and a perennial, Rudbeckia hirta has more lives than some cats. I have had individual plants live in one place for years (a perennial) while others seem to live only briefly (annual or biennial). There are always some around and for that I am grateful. This species has the most variable flower shapes. The petals might be few and widely spaced or they might be numerous and so crowded that the flower almost appears to be a double form. I enjoy discovering each new one.

Rudbeckia fulgida ‘Goldsturm’

Rudbeckia fulgida is often known as “orange coneflower” and has wide, quilted leaves and a spreading habit. Populations in my garden have slowly expanded sideways over time.  When I dig them up to share with friends, the roots are noticeably rhizomatous.  The species has a well-known cultivated form: R. fulgida ‘Goldsturm’. This has been widely available for years and resides in many a garden. 

Rudbeckia fulgida var. fulgida

I actually have a different form, R. fulgida var. fulgida, and it has smooth leaves and smaller flowers. It flowers later in the summer thanks to deer browsing but once they get tired of it (and they do) it flowers from then until frost. You can see in the picture on the left how different the leaves are.

Rudbeckia triloba

Rudbeckia triloba apparently has a softer look – she is known as “brown-eyed Susan”. True to her botanical name, though, she does have leaves with 3 lobes.  This Susan and I only hung out for one year together and then she was gone.

I know you're thinking that these all look alike with their brown centers and yellow petals. But taxonomists assure us they are different! I can attest that the leaves on these are all fairly different if you lined them all up to examine.

But one trait that does keep them together (besides the yellow petals) is the arrangement of the involucral bracts (the green parts that used to enclose the flower bud) on the back of the flower head. Rudbeckia flowers can be distinguished from others in a seemingly endless parade of summer yellow flowers (wait until you meet the Sunflower family!) by examination of the back of the flower head. Perhaps this looks like a typical back of the flower to you, but once you learn to recognize how they are shaped and arranged, you can distinguish several of the most common yellow flowers. Give it a try sometime.

Rudbeckia bracts

Rudbeckia laciniata is one Rudbeckia that does not have a brown center.  The common name is cutleaf coneflower because it has deeply lobed leaves. It has a very wide range throughout the U.S. and is found near me in on a sanctioned rescue site.  It gets too much shade in my yard and hasn’t flowered, so I found this picture to show you the green center with bright yellow petals.  It is one of the tallest in the genus, easily reaching over 3 feet; it also has a reputation for spreading underground so gardeners in small areas should be cautious about using it.

Rudbeckia laciniata
Chris Evans, River to River CWMA,
If you're looking for a dependable full-sun perennial, consider one of these old-fashioned favorites. You'll be happy when they return each year in your yard.


  1. THANK-YOU ELLEN! The mystery is solved! We planted 5 Rudbeckia last year and they were all healthy and pollenator magnets. This year, two did not return at all. We could not figure out what we did wrong. "Listed as an annual, a biennial, and perennial"...perhaps it was not our fault at all:)

  2. Ellen, I've got cutleaf coneflower in my yard--it is the absolute favorite plant of my visiting goldfinches, when in bloom. They cling to those flower heads and just shred them to pieces! There are a couple pictures on my blog--help yourself!

  3. Ellen, Even here in Maine, the rudbeckia (probably R hirta) have already begun to bloom at the side of the road. My favorite Rudbeckia is 'Herbstsonne,' a hybrid cultivar of R. lacinata that shares its lemony yellow color, green cones, and large cut leaves. It grows about 7' tall and is a commanding presence at the back of my garden from late July until frost. They're also visited by the same goldfinch behavior that your previous commenter noted. -Jean

    1. In my garden, rudbeckia hirta is always a biennial. comes up in the autumn, blooms in June, sets seed and dies.
      Someone wrote me a few years ago, complaining about his black-eyed susans... Where'd they go... he'd mulched them, and dead-headed them, the way all the nurseries tell people to do...

      interesting picture of the backside of the flower... I'm always trying to find that unexplored angle... I think you mighta found it....