Outcrops alive with nature
Rock outcrops are among Georgia’s harshest natural environments, subject to extremes in temperature and moisture. Nevertheless, they often are botanical wonderlands, supporting an amazing array of wildflowers and other plants rarely found elsewhere in the state.
Simply put, rock outcrops are places where rock formations appear above the surface of the surrounding landscape. Several of us Georgia Botanical Society members last weekend trudged up one of Georgia’s best-known rock outcrops, Arabia Mountain in DeKalb County, to look at its fall botanical treasures. (Arabia Mountain, like nearby Stone Mountain and Panola Mountain, also is known as a monadnock.)
At first glance, Arabia Mountain, in Davidson-Arabia Nature Preserve, appears to be a big expanse of barren, reddish-gray granite rock, inhospitable to life. But nothing could be further from the truth. This time of year, the outcrop’s botanical splendor can take one’s breath away.
Most of the splendor comes from the yellow daisy, or Confederate daisy, which we found blooming in mass profusion in the shallow, soil-filled pits (called “dish gardens”) dotting the mountain. It was a striking display of color amid the austere granite. In my mind, a human landscape architect would be hard put to imitate Arabia Mountain’s natural displays, which are just as charming and inspiring as any man-made botanical garden.
Our leader, Jim Allison, the reserve’s interpretive ranger and an expert on rock outcrop plants, noted that the yellow daisies “are blooming a little earlier this year, probably because of all the rain we’ve had this summer.”
Also in bloom amid the granite were other less showy wildflowers, but beautiful in their own right. They included the blazing star (purplish-blue flower) dayflower, so-named because its sky-blue blooms wither the day after they open; and Curtis’ milkwort. In some places, the milkwort’s lavender flowers mixed in with the yellow daisy blooms — a gorgeous sight, fit for an artist.
An interesting plant that Allison pointed out was the fame flower, a miniature shrub that grows only about 12 inches high. Because our hike was in the morning, we missed its pink blooms, which open up for a few hours only in the afternoon.
“Fame is fleeting,” Allison quipped.
Granite rock outcrops such as Arabia Mountain are especially rich in lichens that cover the bare rock, and in mosses that grow on the thin soil in the rock depressions. One moss that we observed was black moss, which remains dormant most of the time to tolerate the extreme dryness of rock outcrops. When the moss gets wet, it instantly turns green. We poured a few drops of water on the moss, and within seconds the black had turned to soft green.
In the sky: The moon will be last quarter on Sunday. It will rise about midnight and set around midday, says David Dundee, astronomer with the Tellus Northwest Georgia Science Museum. Mercury is low in the east just before sunrise. Brightly shining Venus rises just before the sun. Mars rises out of the east just before midnight and will appear close to the moon on Sunday night. Jupiter is high in the south at sunset and sets in the west about midnight. Saturn is very low in the east just before sunrise.
