Sky-blue Aster

Sky blue aster adds appealing hue to fall

COLUMBUS DISPATCH

Jim McCormac

October 2, 2011

NATURE

Asters are one of fall’s signature plant groups. More than 30 species native to Ohio tint our woods and fields with blues, purples and whites, providing lively punctuation to the browning of autumn.

The ornate flowers seem magical — and perhaps they are. The ancient Greek goddess Astraea, associated with the constellation Virgo, flung stardust to the Earth, and asters sprung up wherever the celestial particles struck. A less fanciful explanation is that the aster family (Asteraceae) — the world’s largest vascular plant family with almost 23,000 species — has evolved with extraordinary success.

Back in the Wild West days of botanical exploration, a Renaissance man named John Leonard Riddell spent time in central Ohio. He was a roving lecturer, physician, geologist, chemist and politician. He even wrote a science-fiction book about space travel. But, above all, Riddell is immortalized for his work as a botanist.

Riddell’s travels took place at a time when new discoveries were routine, and the Ohio frontier was not yet well-documented. He was among the first botanists to step foot in the largely unexplored habitats that cloaked the core of Ohio. One of his finds bears our state’s name: Ohio goldenrod.

But even Riddell, used to new discoveries, must have been elated one fine September day as he investigated the bluffs over the Olentangy River near Worthington. Looking down, he saw a plant bearing panicles of stunning azure flowers, as if its branches held galaxies of starry blossoms. Riddell had found what would become known as sky blue aster, and he named the plant for the river where he found it: Aster oolentangiensis (now Symphyotrichum oolentangiense).

Sky blue aster is a standout in a pageant of botanical beauties. All of the blue-flowered asters are knockouts, but Riddell’s find is hard to match. A healthy plant can tower 3 feet or taller and sport dozens of deep blue flowers. Such a specimen would draw oohs and aahs if planted in a sophisticated gardener’s bed.

Naturalist Jim McCormac writes a column for The Dispatch the first and third Sundays of the month. He also writes about nature at jimmccormac.blogspot.com.