Help me ID these weeds

I live in inland southern california which is a chaparral type climate but I live a bit in the hills so there are actually more trees even though it is still dry and hot in the summer.

If anyone can ID these weeds, I'd like to know if I should pull them or let them grow more and propagate.  I'm purposely letting dandelions grow since I eat them and they also improve the soil. 

















any ideas?

The last one looks like a purslane relative.

I want to know what the first one is too, because I feed it to my tortoise all the time.

ya the first one looks alot like a dandelion but is much bigger and the leaves dont all come out at ground level.

The last one isn't a succulent so I dont think its related to purselane.  They are tiny and each plant only has two leaves.  Its kind of like duckweed but on land.

the first is NOT dandelion.

the second looks like sow thistle, looking at the blooms will help.

the last is NOT purslane, looks like Dichondra

Third photo looks like Jerusalem Artichoke or a relative in the sunflower or aster family.

1st one is a wild lettuce (Lactuca sarriola) it gives a white sap it said to be good for colds. leaves are edible when very young.there are two variety one wuth long round leaf and one with those jagged edges as in the pic, sometimes you can see wild lettuces with both shape leaves when grown... but when they are young leaves are long and you can tell they are wild lettuce by the soft spines along the outside of the central nerve of the leaf


2nd one looks like sow thistle (Sonchus oleraceus) it also gives white sap and also is edible here in Spain we call them "cerrajas" and people give it to chikens and partridges

First one is a lettuce relative (the ancestor to our lettuce). It tastes terrible, but someone here on permies was saying if you put it in a blender it's a great fertilizer for your plants. Second is sow thistle, which I love to eat. The third one looks like young echinacea to me.
John S
PDX OR

#3 looks like Jerusalem Artichoke.

Patrick Mann wrote:#3 looks like Jerusalem Artichoke.

I agree, dead ringers for what I have sprouting in several -places where I planted Jerusalem Artichoke last fall. Of course, what I think are my artichokes sprouting could be something else