Monday, September 5, 2016

Ohio's orchid species can grab attention, but many species are threatened

Yellow-fringed orchid, Platanthera ciliaris

September 4, 2016

NATURE
Jim McCormac

For the orchidophile, a trip to Colombia’s tropical forests would be living a dream. The country harbors several thousand species. Orchids new to science are routinely discovered.

In the world of flowering plants (angiosperms), the orchid family might be the most diverse: An estimated 24,000 species exist worldwide. The only rival is the sunflower family, which has about the same number of species.

For Ohio orchid hunters, prey is far scarcer than in Colombia. Nonetheless, 46 native species are found in the state. There is probably at least one species in every county.

The range of Ohio’s small suite of indigenous orchids represents an artist’s palette of color. Pink, orange, ivory, emerald, purple and other colors paint a fantastic diversity of flower structures.

Among our showiest orchids are those in the genus Platanthera. There are (or were) 12 Ohio species, and most are big and spectacular.

I recently had the pleasure of viewing perhaps the most spectacular Platanthera orchid of all: the yellow fringed orchid, P. ciliaris. This plant is otherworldly in appearance and sure to stop people in their tracks.

A robust yellow fringed orchid rises to almost 2 feet tall, capped by a robust cluster of dozens of flowers. It is these flowers that cause jaws to drop. Their color is a gorgeous orange-yellow, a hue not seen elsewhere in nature, at least around here.

Each flower is held on a long, slender pedicel. The flower’s lip, or lower petal, is divided into a spectacular brush of fringes, as if it were briefly shoved into a paper shredder. A long threadlike spur juts from the flower’s other end, providing interesting architectural punctuation.

As befits such a showy plant, its principal pollinators are beautiful as well. While I was admiring these plants recently, several spicebush and Eastern tiger swallowtail butterflies were busily working over the colony. Swallowtails do the heavy lifting of pollination for this species.

Yellow fringed orchid is listed as threatened in Ohio, and there are essentially only four populations. Some occur in the Oak Openings area west of Toledo, and reportedly a small population exists in Hocking County. A small colony maintains a tenuous foothold in Washington County.

The mother lode of this orchid occurs in Shawnee State Forest, Ohio’s largest state forest and a site unbelievably rich in biodiversity. That’s where I made the accompanying photograph on my Aug. 7 trip.

Ohio’s orchids are benchmarks of habitat health. Our scorecard is not good. Of the state’s 46 species, eight are endangered, six are threatened and eight are potentially threatened. Two of our six federally threatened plants are orchids.

Saddest of all, four of Ohio’s orchids are considered extirpated: They no longer occur in the state.

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

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