On Tue, 25 Jun 2013 04:01:21 +0000 (UTC), Danny D. wrote:
On Mon, 24 Jun 2013 19:05:01 -0700, Roy wrote:

The pods develop from the flowers.
The pods contain the seeds and they go from green to black as the ripen.

Hmmm... I was thinking these things were the actual seed pods:
http://www2.picturepush.com/photo/a/...g/13403320.jpg

Your arrow is pointing towards an immature silique, the fruit of the plant...
that is a maturing ovary (aka gynoecium). If you cut one in half crosswise,
you'll see two chambers, each with seeds.

I still can't tell which of many possibilities your particular members of the
mustard family are (there are a lot of them in California!), but it is
indeed a member of the mustard family, now mostly called the Brassicaceae, but
Cruciferae is the older classical name for this family. Typically
four separate sepals, four separate petals, six stamens (often two short and
four long) and a two-chambered ovary.
http://waynesword.palomar.edu/images/silique1.gif

Usually edible, though some are not. Some species pick up lead and other heavy
metals from the soil (remember all the years of leaded gasoline), which
can render them toxic.

As always, identify a plant properly before feasting on it.