Tuesday, September 17, 2013

September Sunflowers - Helianthus spp.

September is the month for myriad golden yellow asters, crowned by one or many of those confounding composite flowerheads.
Dozens or even hundreds of tiny tubular disk flowers cluster in the center, surrounded on the periphery by cleverly aligned ray flowers, each bearing a singular "petal", uniting to create the illusion of a much larger single sunflower or daisy blossom, the classic "flower" of a million childhood coloring books.  

This native narrow-leaved or swamp sunflower growing alongside Plank Road in Lee County bears a strong resemblance to the western species of sunflower first cultivated by native Americans some 5000 years ago. 

In one of our earliest examples of horticulture, these domesticated sunflowers made their way to Western Europe on the ships of Spanish explorers where they were further refined and eventually perfected by Russian horticulturalists into the single-headed "Russian Giant" which ultimately returned to its American roots in the 19th Century as a highly popular garden plant and profitable agricultural crop.  

As the stifling heat dissipates across the Carolinas with the approach of autumn, even the casual observer can't miss the many sunny-hued asters at the height of their later late-summer splendor. Some, like the pale-petaled "giant" woodland sunflowers pictured above and below, are true sunflowers, one of about 50 species of Helianthus native to the Americas.

Though the flowerheads are not particularly large, "giant" refers to the remarkable height attained by the mature plants in late summer. Some of the individuals pictured below are well over ten feet in height, with the specimen in the left rear of the picture topping twelve feet.

The "petal-bearing" ray flowers are sterile, but the mass of disk flowers at the center of the flowerhead will produce the abundant crop of the seeds for which the sunflower is famous.

The blossoms offer nourishment to an array of pollinators, including bumblebees and painted lady butterflies, while the seeds are a favorite of avian wildlife, particularly goldfinches.

Some of our native sunflowers bear a strong resemblance to the ever-popular cultivated varieties;

but with over 20,000 known species in the Aster family (Asteraceae), all sharing the sunflowers' composite flower structure, it can be a bit difficult to distinguish the true sunflowers from the golden asters, coneflowers, coreopsis, black-eyed susans and tickseed sunflowers which quite often share the same habitat along roadside and wood margins. 

If you, like us, are determined to get to know our native sunflowers, however, a rural roadside in September is a great place to start...

and you're sure to be greeted by a golden horde, gazes fixed in the east, just as eager to make your acquaintance.

After all, in the words of Ginsberg's "Sunflower Sutra"

..."we're all beautiful golden sunflowers inside..." 

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