Question
I have this weed all over my lawn. I have bermuda grass. This is a very rough feeling weed. I have several pictures at my website at:
http://www.reisingerfamily.net/weed/index.html  

Answer
Hi, Peter - Nice photos.  

To be honest, I should not be answering this - I am after all the Long Island Gardener, and I have a feeling you are nowhere near my part of the woods.  Not even close.

When I venture out into unknown territory, I cease to be an Expert.  I've tried it - and I'm often wrong.  We learn from our mistakes.  And I have learned plenty.  But you don't want a guesstimate on this.  You are asking for Expert Advice - and if you lived in Zone 5, Zone 6, Zone 7 or even pushed it to Zone 8 - I would have great answers.  But put me in - where are you???? Texas?  Hawaii?  Arizona?  California?  I don't know nuthin' 'bout grass from Hawaii.  You have different bugs, different diseases, different climate, different grass!  Even the water is different.  Your fungus is different.

So before I open my big mouth here, I want to issue this little caveat.  I am giving you my best guess.

Here goes:

First the bad news.

It's SO hard to i.d. a weed from a photo - you have taken some great shots, but the weed is out of the ground, I can't tell the growth habit, no idea if there is a flower there or not, I'm not really sure how big the leaves are, I can't even tell what USDA Zone or State you're in and several other keys to making a positive i.d. that will (I assume) lead to its complete eradication.

The good news:  I can send you to several websites that are designed to help us with this.  When you think you have a few suspects lined up, let me know what you think they might be, and I can confirm (with the right background - I am definitely going to need your USDA Zone, which can be found if you'll email me the name of your nearest big city) the identity of your suspicious weed.

Try the do-it-yourself identification of alien weeds at the Virginia Tech website (www.ppws.vt.edu/weedindex.htm) and at University of Illinois Interactive Weed Identification website (web.aces.uiuc.edu/weedid).

By the way, the Illinois service is the highest rated page of its kind on the internet but it requires a basic understanding of the terminology -- or a lot of patience.  But both websites are excellent.  I have others, but these will do for now.

Now, I have a question for you.

Are you taking good care of your Bermudagrass, Peter?

Because I may not be an Expert in warm season grasses, but I know that if you take good care of good grass, it won't get weeds.

Let's take your Bermudagrass (Cynodon dactylon).  

This is a thick, spreading grass that shows no mercy when it comes to unwanted invaders - usually.  In fact, it is so aggressive, that the species itself is a considered an invasive weed.

Bermuda needs full sun to thrive.  It does not like shade.  Are you growing your Bermudagrass in the brightest day of full sun?  Or is there a little shade in this situation?  

Shade would shake up the Bermuda very quickly.  Once you do that, anything can happen.  Weeds from outer space.  Anything.

Bermuda also needs to be mowed correctly.  Mowing is not a simple task.  Mowing dry grass with a razor sharp blade, at the perfect height for that variety - frequently - will yield a strength and vigor you cannot get any other way.

Rich soil with a pH of 6.5 - which is how Bermudagrass likes its soil - is not the kind of place weeds like to grow.  It's like putting your grass on steroids.  No weed will mess with grass on steroids.

It is my understanding that Bermudagrass is a Nitrogen-guzzling plant that needs to be fed A LOT.  Have you done that lately, Peter?

There's a Bermudagrass webpage at the Pike Family Nursery website (www.pikenursery.com/stories_php_loc_02_03_05.html) that does a good job of summarizing the Bermudagrass personality.  

One statement in particular stands out, however: "A healthy, well-fed Bermuda lawn rarely has a weed problem."  My sentiments exactly.

Although I take exception to their advice about using weed killers to zap weeds, this observation about healthy Bermudagrass squeezing out weeds really hits the nail on the head.  Because it's true.  University research gets the same results over and over on all the popular grasses.

Since I think you are probably in some kind of frost-free zone that does not have things like annual weeds, I can't begin to give you any instructions about pre-emergent crabgrass killer for your lawn.  But the truth is, you don't need anything like that.  And anyway that's so bad for you.  To use the frequent illustration of how bad DDT is for us, a vial the size of a pack of Lifesavers, poured on the skin of 4 kindergarten children, will kill 2 of them.  And DDT is considered one of the safest pesticides on the market.

So organic is a very nice thing to be.

Go ahead, Peter, try to narrow down the weeds universe with those websites above.  If you have any theories, we'll go down the list and see what's possible.  But in the end, you just want to get rid of these unwanted guests.  They're messing up your carefully tended lawn.  One of the kids can bring in the weed to Show And Tell after we i.d. it.  Then they can tell everybody in the class how Daddy was so smart he did not even have to put those bad pesticides on the lawn to kill the weeds - he just tricked them into leaving.  Daddy is so smart!

Thanks for writing, keep in touch - if you don't mind the unexpert advice!