Oklahoma Plant ID

Below are pictures of weeds growing in my yard. I would greatly appreciate help identifying these plants or resources for identifying Oklahoma weeds/wild plants.
Thanks! Sam

Welcome to Permies!

I have never been to Oklahoma but will give you my guesses…

The first one is definitely a mustard family member, probably of the genus Cardamine. Something in me wants to say “Cuckooflower”—Cardamine pratensis, a beautiful spring flower that covers hayfields here in mid spring. But as I am not an expert in Oklahoma flora I can’t get it down to species level.

Plant 3 is one I have seen before and eaten plenty. I think they’re whitetop mustard, but it’s not easy to confirm that until they’re blooming. I think Lepidium draba? They are good, quite hot.

Plant 4 is a thistle of some kind. I don’t know which species exactly. They sort of look like canada thistle but I am not confident enough to say for certain (not a thistle expert)

Plant 2, I have no idea.

It is lovely to see all of these spring weeds. Here in New England it just snowed today after the first week of warmth!

I hope this helps!

Actually, could plant 2 be some kind of galium/bedstraw?

I grew up in Muskogee, Tulsa and spent time in Jay.

I have never seen plant 1.

Plant 2 and 3 look familiar though I cant put a name on them.

Plant 4 is definitely thistle of which there are many varieties.

I would suggest removing the thistle while it is still young and before it goes to seed.  It has a tough root.

It is easier to ID plants when they bloom.

#1 looks similar to knot weed.  The key word here is similar.  But given that you are in a much dryer area than I am, that might allow for the difference from what I see around here.

I've never seen the first plant but the inflorescence indicates it's a cruciferous. So I got out my Texas wildflower book and one description matches:
Lepidium montanum, or mountain pepperweed, also known as pennycress. Leaves and seeds are edible and taste peppery.

Here is a thread on pennycress in case that is number one:

https://permies.com/t/40126/Pennycress