False Sunflower

Heliopsis helianthoides, a.k.a. smooth oxeye, has ‘false’ in its name based primarily on its reproductive structure which differs from true sunflowers. This is worth a closer look, so let’s enter the reproductive world of the Aster family. Flowers in the Aster family are composite. A bloom of a coneflower, dandelion, black-eyed Susan, sunflower, or goats beard, for example, appears as one flower on its stalk, but each flowerhead is actually made up of many smaller flowers, called ‘florets’ that comprise the whole. There are disk florets comprising the center (male and female organs) and the long, narrow ray (petal) florets, which are the (usually) sterile female parts. Therein lies the difference. False sunflower’s ray florets are fertile unlike the florets of sunflower.

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Long and narrow, each flower has its own reproductive organs making up the whole. In true sunflowers, the petal-like flowers are usually sterile. False sunflower, on the other hand, is not a true sunflower because its ray flowers are fertile.