Wednesday Search Challenge (2/13/13): What kind of flower is it?

I went out for a run yesterday from the Googleplex.  It was a lovely day, around 60F, with a light breeze coming off San Francisco Bay.  

I was really impressed when I discovered the following hillside of golden flowers blooming about 1 mile from the Plex, only a few feet from Stevens Creek, which flows into the bay.  (You can see the bay in the background--all that water is the southern tip of SF Bay.  The fence runs along the trail I was on.)   

This was too early for the mustard to be out, and too early for other yellow flowers I know about... so I stopped, pulled out my phone and took these pictures.   (You can click on them to see the full size image.)  

As you can see, it's a fairly small flower that loves to grow in large swathes of flowers.  In this case, this  hillside is the top of a landfill covering, so this is disturbed earth, and consequently I have no confidence that this is a native plant.  

The leaves are slightly wooly, a little sticky, and fairly aromatic when I rub them between my fingers.  The stem is square in cross-section.  

The challenge for today is simple to state, but difficult to answer: 

   What kind of flower is this? 

If you happen to know, please post the answer to the comments (but I'll hold back on posting your correct answer until other people have had a chance to try and work it out).  

Now the truth is... like you, I don't know what it is either.  

So let's try to solve this problem collectively!  I can get to this field of flowers easily.  (It's just a few minutes from my office.)  

So... Tell me:  What other information should I get in order to make a positive ID?  Let me know, and I'll run out there, find out, and post an update to the blog.  

If you manage to figure this out via just plain web-search, I'll send out a Google t-shirt to the first 3 people who can publish the correct answer AND their solution path!  

As usual, let us know what you did to solve the problem and how long it took you to figure it out.  

Search on!  (Botanically speaking...)  

_______________________

Later (9:30AM, PDT)  

I just came back from the field and found that all of the flowers are closed!  I'll have to go back later this morning to get some close-up pictures of them in the open state.  

In the meantime, here are a couple of closeup pics I took...  you can see the hairs on the leaves very clearly.  And I also discovered that my previous note about the cross-section was wrong... the stems are NOT square:  they're pentagonal!  (See image below--click to see at full resolution.)  

Note the texture of the skin--slightly hairy, definitely slightly sticky and fragrant when you touch it.