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!
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.
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 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 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.