Thursday, May 19, 2011

Butterweed, Packera glabella

Crop field in Delaware County, Ohio
As you drive across Ohio's farmlands, are you seeing acres of yellow right now?  If so, you're most likely seeing what I like to call butterweed.   It looks like giant golden ragwort, if you're familiar with the genus Packera (formerly our Packeras were in the genus Senecio). This plant is native in the central and southeast U.S., but has rapidly expanded across Ohio in recent decades.  Just take a look at the range map for Ohio from USDA Plants:




It's all over central and western Ohio, but by looking at this map, you'd think it was a rarity.  It's even showing up in my front yard as a weed!  Why has this plant expanded so rapidly?  Is it taking advantage of no-till agriculture?  Is there something else to the story?  I'm not sure, but I bet that it grows in every county in Ohio's corn belt plains, and on this map, it barely registers in a few Ohio counties.

Plants get around- they move, and they can do things that we never expect.  And that's why I think they're incredibly cool.  Look out Pennsylvania, butterweed may be headed towards you!

Tom

p.s. (I bet it's probably there already)

6 comments:

  1. My wife was just asking me about Butterweed fields yesterday. Tillage or planting methods don't seem to make a difference. I've seen solid stands of Butterweed in no-till, reduced tillage and plowed fields. Twenty years ago, it was only known in four Ohio counties. Now it's everywhere. It seems that the plant moved up from the south. Maybe this is another portent of global climate change.

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  2. Steve- It certainly is a strange phenomenon. Thanks for letting me know that you've seen in it in all types of crop fields.

    Tom

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  3. Tom, let me add it is found in every county of S.E. Ohio. I have seen it in the Pataskala and Newark area, Lorain Co. and even around the Youngstown counties. I'd be willing to bet it's in all Ohio counties. Besides ag fields I have found it in wooded areas and wetlands as well. An interesting dilemma for resource managers. Invasive yes, but is it classified as exotic?

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    1. Native vs Exotic is indeed not always a straight-forward distinction. When a disturbance-adapted species expands its range due to human activities, but not due to direct introduction, it is basically a matter of opinion. The problem is that our concepts are often more simple than reality. As a practical matter, we don't want to treat species like this one as appropriate conservation targets as rare species, even if they are currently rare. This species does not need our help, and may actually be a threat to some rare elements of the native flora.

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  4. I have seen Butterweed covering ag fields in southern Illinois, in openings in wet woods, and now in my front garden in total shade. Anything that wants to bloom in that shade is all right with me. The stalk is also reddish, quite an attractive little weedy flower. Apparently biennial, as the rosettes have already formed in my garden.

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  5. A colleague, Pete Woods, found this in Beaver County< PA last spring. We saw that Kartesz had it as introduced in Greene County, but we were not convinced just by looking at the map that it was not native here. Thanks for posting this; it convinced us that we do not want to consider tracking this as a rare native species in Pennsylvania! Turns out Joe Isaac got it in 2003 in Greene County. It has been documented from Allegheny County as well. -- Steve

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