I know you know what arugula is, we've all seen it in the produce department.  But have you ever seen it blooming?  Only if you've seen it growing.  When it's in bloom, you can see how it's related to broccoli, cabbage, radish.  They are all crucifers.  See the four petals in the shape of a cross?  All crucifers bloom like this.  
 

Botanically, they are all known as Brassicaceae, or the older name Cruciferae.  The family includes mustards, cabbages, broccoli, cauliflower, Brussels sprouts, bok choy, horseradish, radish, wasabi, turnips, collards, and kales.  Arugula blooms white, broccoli yellow, and radish blooms are often pink.  We let them all bloom so they can go to seed.  Then we collect the seeds, and start all over.  We haven't bought arugula seeds in years, but grow three crops each summer.  
 

In this picture, the arugula bed has been invaded by a bit of Queen Anne's Lace, see it at the bottom?  It's the one on the left with feathery leaves.  On the right is dandelion.  And the yellow flowers are blooms of bok choy that got tossed in the bed for fun.  I also see some chickweed, and morning glory, but don't look at them.(They're weeds!) and need to go away.  The rest can stay.  
 

Speaking of weeds, it's time to hit the garden, before it gets too hot.  Talk later.

 

HAPPY GARDENING!!!