Wednesday, November 18, 2009

Quiz Time!! JohnnyHank Nails It!!

JohnnyHank says it is Strophostyles helvula. Librarian or not, that is the right answer. Here is a photograph of the flower.

Some of you may be asking yourself "Doesn't Strophostyles helvula have lobate lateral leaflets?". That is where I was a bit tricky. This is actually S. helvula var. missouriensis which lacks the lobes on the lateral leaflets (the typical variety has lobed leaflets).

Vegetatively the genus Strophostyles can be distinguish from Amphicarpaea bracteata, which it most resembles, by its erect stipules. Amphicarpaea looks exactly like Strophostyles helvula var. missouriensis but has appressed stipules. By clicking on the photo above you can see the stipules in the enlarged version. They are perpendicular to the stem.

Lesson learned; Librarians make great botanist. If only it worked both ways.

Thanks to everyone for playing!

15 comments:

Prodige said...

looks like
Amphicarpa bracteata (L.) Fern.
but I m not sure

ben said...

Phaseolus polystachios?

Justin Thomas said...

Though very close, the plant is neither Amphicarpaea nor Phaseolus.

Keith said...

Whatever it is, I like how the middle leaflet doesn't lie in the same plane as the other two.

Prodige said...

Desmodium?

Justin Thomas said...

Nope. Not Desmodium.

Kirk said...

Maybe one of the Dogbanes?

Nick said...

resembles Apios americana, though I can only make out 3 leaflets in the picture whereas A. americana usually shows 5-7.

Justin Thomas said...

Sorry, it is not a dogbane or Apios.

It isn't a terribly common species but it does occur throughout the eastern and Midwestern portions of the US and into Canada. It is a bit more common in the southeastern US. It is faithfully trifoliate.

If no one guesses correctly by late tonight I'll post the answer.

JohnnyHank said...

Can librarians guess?
Strophostyles helvola?

Cdr said...

this guess is more than partially based on how the mind of Justin and the minds of many other great botanists work:

Clitoria mariana?

I'm not familiar with this plant but am guessing based on leaf arrangement and range.

is it getting hot in here?

Justin Thomas said...

We have a winner! See the post for details.

Sadly, it is not Clitoria mariana.

Scott said...

Good quiz, Justin. It's good to see that we still have people visiting the blog after going so many days without a new post.

I have been very busy lately, and hadn't really had time to spend with this quiz. When I saw the photo, I knew I didn't know what it was immediately. I was planning to spend some time tonight trying to figure it out, but JohnnyHank beat me to it. Nice work, JohnnyHank!

The reason I didn't get to Strophostyles in the keys I used in the brief time I spent trying to figure this out was that I didn't see stipels at the base of the leaflets in the photo. Are they there and very small? Can you see them in the enlarged photo?

Scott said...

Wow, Justin... that flower photo could be part of an after-hours slide show...

Justin Thomas said...

If I use my imagination, I think I see stipels. In reality, I've never looked that closely. They could be small or early deciduous. The photo was taken on my property, so I'll give them a gander next spring and let you know.