Thursday, September 9, 2010

Nodding Rattlesnake-root

Your blogger is dwarfed by a gigantic, 11-foot Nodding Rattlesnake-root, Prenanthes crepidinea.

While on a recent botanical foray in the Cincinnati area, Brian Riley, Dan Boone and I stopped by Fernwood Park. not to admire ferns, but rather to seek this beast of a plant; a species that I had seen in flower only twice prior.

No mystery where the "nodding" in the name comes from - the flowers droop noticeably on arched pedicels.

This species and others in the genus Prenanthes are the so-called "wild lettuces", and exude a milky sap if bruised. Most are rather homely plants, although this one does have a bit of an allure when seen closely. The buttery yellow flowers are rather attractive, although I don't think you'll see the gardening crowd - even native species advocates - clamoring for Nodding Rattlesnake-root any time soon.

For such jumbo plants, the various species of wild lettuces key out on rather minute characters. Prenanthes crepidinea separates from most of its brethren by these pubescent phyllaries - the greenish "cup" that the flower nestles in. You can easily see these whitish hairs in the shot above.
Nodding Rattlesnake-root is essentially a plant of the Midwest, and was once thought to be quite rare in Ohio. And it is, if mature flowering plants are what you seek. The plant occurs primarily on floodplains and stream terraces, and typically never makes it past the stage shown above. Rosette leaves shoot forth in April, last a month or two, turn yellow, wither and die. Once we learned to recognize these young plants for what they are, we began finding Nodding Rattlesnake-root practically everywhere.

But only when some sort of disturbance opens the canopy and exposes the plants to a good jolt of sunlight do they fire from the ground and elevate to Jack-in-the-beanstalk proportions.


Justin Thomas said...

Great post, Jim! I occasionally stumble into colonies of this beast in my travels, but have yet to see it bolt and bloom. Impressive! I hope to some day stand in its shadow.

Jim McCormac said...

And I hope that you DO one day stand in the long shadow cast by an elephantine Nodding Rattlesnake-root, Justin!