Question

parsley 1  

parsley 2   3 of these are growing in my back yard in North Central Florida. What are they? My first thought was parsley, but after looking it up i'm not so sure. I just noticed them this morning and they only have one single flower at the tip of each plant, which is yellow and old, closed up, and petals falling off in the picture, not a cluster like parsley. The leaves/stems are opposite.

Answer
Hi Shelly,

I think you may be right that it is in the parsley family, but I can't tell which member from this one, pitiful specimen.  The first photo looks like a spanish needle plant which has already lost it's ray flowers, but in the second picture, the flower looks totally different.  Could it have been sprayed with an herbicide?  Maybe you could resend it if it makes a few more flowers.  

The parsley family has some really nasty members, like poison hemlock, and hog parsley, so don't taste it.  Also, you are in Florida, where almost everything grows, so there is no guarantee it's a native weed.  You could try taking it to your local nursery and actually seeing the plant, they may better be able to give you the exact species.
Thanks,
Susan