Friday, April 25, 2008

Vegetative Obscurities

On a recent expedition to southern Ohio, we encountered many rare and interesting plants. Not the least of these was a gorgeous, Lilliputian gentian. Pennywort Gentian, Obolaria virginica, is more common than may be thought, but it is easily passed by.

Quite the stunner, eh? A few inches tall constitutes a whopper of a Pennywort Gentian, and some plants barely project out of the duff of last fall's leaf litter. The Gentian family is not a big one in our region, and this is the earliest of their lot to bloom.

Quarter for scale. Truly a micro-gentian, but as almost always the case with the tiny and obscure, upon close scrutiny they reveal their charms.

A while back, I blogged about the "discovery" of a new species. Well, we revisited the site where I found Reznicek's Sedge, Carex reznicekii, 16 years ago. And lo and behold, there it was, doing just fine on its dry oak-shaded hillside in Jackson County.

Tuft of Reznicek's Sedge, looking much like a sterile clump of grass. Obscure in the extreme, sedges in this most interesting and rather showy group are often overlooked.

By lying on my belly I am able to take us in closer to the "meat" of the plant. Standing upright, one would think nothing of this sedge, nor notice anything other than the clump of leaves. However, it is in full fruit and by getting down on its level and parting the foliage, we can see the fruiting clusters, necessary to examine for positive identification.

Now we're right in there. This is a culm, containing both male and female flowers of the sedge. The slender, reddish-brown spikelet are the male, or staminate, flowers. The larger green beaked units below are the pistillate, or female flowers which form the fruit. In sedge-speak, fruit are called perigynia, and this specimen of Reznicek's Sedge is in its full glory.

What good is such an obscure plant? Might ask an ant. Often, when a plant forms fruit very near the ground, like this species, ants are the agents of dispersal. No one knows for sure the mechanics of pollination and seed dispersal with this newly described species, though. Of all the things growing in wild Ohio, only a tiny fraction are thoroughly understood. For a good many species, we know nearly nothing about their life history.

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