[5][6] Rudbeckia flowers feature a prominent, raised central disc in black, brown shades of green, and in-between tones, giving rise to their familiar common names of coneflowers and black-eyed-susans.

All are native to North America, and many species are cultivated in gardens for their showy yellow or gold flower heads that bloom in mid to late summer.

The species are herbaceous, mostly perennial plants (some annual or biennial) growing to 0.5–3.0 m tall, with simple or branched stems.

Rudbeckia is one of at least four genera within the flowering plant family Asteraceae whose members are commonly known as coneflowers; the others are Echinacea, Dracopis, and Ratibida.

I have chosen a noble plant in order to recall your merits and the services you have rendered, a tall one to give an idea of your stature, and I wanted it to be one which branched and which flowered and fruited freely, to show that you cultivated not only the sciences but also the humanities.

Its rayed flowers will bear witness that you shone among savants like the sun among the stars; its perennial roots will remind us that each year sees you live again through new works.