Regards,
Arif.

It's an Oxalis of some kind. I couldn't even guess which species, though.

Where I am it would be oxalis pes-caprae / Bermuda Buttercup. But there may be similar oxalis that I'm not familiar with.....

A few possibilities:

Oxalis pes-capre: http://www.efloras.org/florata...

Oxalis corniculata: http://www.efloras.org/florata...

Oxalis variabilis: http://www.efloras.org/florata...

I remember my grandmother calling it a Buttercup and honestly it has the shade of butter. Let me check. Oxalis pes-caprae it is as to Oxalis variabilis(Oxalis purpurea) I was going to post it next, I have the photographs on another machine will post latter. Oxalis corniculata, no photographs have not seen it as yet in bloom but that to is growing wild in some corner. Thank you Lin and other for taking out the time .
One question, I want to grow these Buttercups. I have a photograph of a whole field covered with it, mouth watering. Is it a good idea or a bad, should I keep it contained in a pot?
Regards,
Arif.

Here, most people would tell you not to plant it as it's 'invasive'. I have it all over my 1 1/2 acres. There's no way I could eradicate, nor would I want to. It's pretty and the bees love it. I'd just deleted the pics that I have of it, but wiil take more in the morning.

Let me see if I can link to a photo with ATP...
The thread "What's blooming in February..." in Pacific Coast Gardening forum

Well, that did not bring me to the specific pics, but if you scroll up 12 posts, you will see the pics of the oxalis .....

I thought so when I saw the field covered with it. It was looking very pretty and as you also observed the bees and insects love it. Likes moisture though.
Regards,
Arif.

Well, we're in our brief as it is rainy season, so it works well. It will dry up when the soil does....we get about 9" annually.

. Terrace the spot with well draining soil it will shift to the wall and maybe a few new things may start there. On both, the wall and the flat surface. Ca I can understand but what is zone 23?
Regards,
Arif.

Zone 23 is what we are in terms of Sunset zones. Sunset magazine and the Sunset Western Garden Book has more accurately defined weather zones for us. Sunset zone 23 is sub-tropical. Sunset being pretty much the bible for us here.....I never pay much attention to what we are in terms of the USDA guidelines....it's either zone 9a or 9b. 20 miles from here to the coast.

Wow! Sub Tropical, North I suppose?
Regards,
Arif.

Well, 60 miles North of San Diego...North of the Mexican border. It's a favored growing area so we have lots of growers and nurseries, both wholesale and retail. Of course, the down side of that being that we have a harder time with the items requiring more chilling.
edited to add that we will be moving....if it turns out that we move 20 miles furether inland, then I will have more winter chill for the items that require it, but also more heat and drier. If we move to the North end of the state, we would have huge amounts of rainfall and quite different growing conditions...allowing me to grow all of the hydrangeas and shrub fuchsias that I want...lol..Gardening here means high water bills and the costs will just keep rising...

Don't mind me, learning.
Regards,
Arif.

We're all learning...continually.

If we move to the North end of the state, to Crescent City, 20 miles south of the Oregon border, we would be in an 'oceanic climate' with 60-some inches of rain. We would be having a 43 degree day today instead of the 63 we will have here today. We would not have hot summer weather. There is a strong inclination toward tsunamis there, though they're working on that problem and I'm pretty sure we would stay inland a bit away from that threat...lol.

But wow! 60-some inches of rain! No continual hose watering...no high water bills. properties are cheaper, jobs far fewer...and you have to learn to make do with less sunshine...lol...

There is a lot that can be done in that kind of an area but there will have to be a complete mind change. Temperate rain forest change, quite an interesting kind.
Regards,
Arif.

I've lived in Washington state before, far Pacific Northwest, northernmost. We were in the rain shadow and so received only 15 inches of rainfall annually, but true....the lack of sunshine can be quite depressing and requires a different mindset.

. It would be fun to try shade loving plants. Cool and moist area with enough rainfall to grow rice. Lets say some plants from Laos and Cambodia area. Quite a variety there that some would give an arm and a leg to grow. Anyway, warmth has its charm. If you want more sunshine then you are more then welcome here. Would you prefer 45c and a UV radiation of 11 and above? You will end up loving that cool and moist area.
Regards,
Arif.