Growing wild here. Photos are from early August.



Buds


Seed pods - immature


Leaves - alternate

maybe an Evening Primrose (Oenothera macrocarpa)

I was thinking primrose as well.

Looks like Oenothera to me also. There are a few found here in Fla. Could it be the native C. laciniata?: http://hawthornhillwildflowers...

Oenothera spp. typically have four petals (four sepals, too). But there can be the odd multipetaled flower. At any rate, O. macrocarpa flowers are born singly, not several on a stem, leaves with a stem and pods are unmistakably different. Pay particular attention to the seed pod for identification: round ones are rather uncommon in this genus.

I also thought of Turnera, I've often confused the yellow flowers of Oenothera and Turnera. Yellow Alder (Turnera ulmifolia) is another Fla. native but the leaves of your plant don't look quite right for that one to my eyes.

Thanks everyone. Rick, thank you for the info. about Oenothera spp.. That will save me a lot of looking & time.
It is not Turnera ulmifolia. The petals are the wrong shape not to mention the leaves. The petals of T. ulmifolia almost come to a point at the center of the outer edge -- my plant does not; they are more squared off on the center of the outer edge.

Back to the drawing board.

The seed pods and flowers are like Linum, but I haven't found one with leaves to match. It could be in Linaceae, the only genus in Florida appears to be Linum.

It could be an escapee.

I think you're on the right track with Linum Janet. Checking it out.....

Found a few Linum that grow in Fla. but the only ones I could find with yellow blooms are:

Florida Yellow Flax (Linum floridanum)
http://florida.plantatlas.usf....
http://florida.plantatlas.usf....

Florida Yellow Flax:
Linum floridanum var. floridanum
http://florida.plantatlas.usf....
http://eol.org/pages/1283038/o...

Thanks Lin. I had already checked out the L. floridanum & that's not it -- petals wrong - separated not overlapping. I can't find any photos or much of any description on L. floridanum var floridanum but I did find a reference saying it's found in wet pine savannas & mine is in a completely different situation.

Maybe linum striatum?

Thanks Jeanie. I don't think that's it but will keep it on my list as a possibility. The leaves seem too narrow & the bloom petals seem too separated. Again, it's somewhat difficult to find much in the way of close up photos or written descriptions. I did find a description on it which says leaves at the base are opposite but become alternate as you go up the stems. That is not something I had thought to look for when taking photos that day. I was out there today but could not find anything b/c we had the bush hog in a few weeks ago. But there is still time for them to re-grow so I will keep looking and when they do I will take more photos & observe more closely.