it occurs to me what i'm really looking for, maybe, is a grass...? if so, what type should i get that takes little water, yet tolerates it, and doesn't need to be cut?

Hmmm, I don't think there is such a plant, but if you ever find one, please post it here! I use two plants between flagstones: elfin thyme and dichondra. The elfin thyme creeps, but slowly. The dichonrdra creeps quickly right over the stones and into the flower beds. Dang. I once planted a grass, zoysia, that you never mow and that looks just like irish moss. It ate whole patios. I am still digging out flagstones (gave up on getting rid of the zoysia!).

If you have plenty of money, time, and water, you could buy flats of Irish moss, cut it into one-inch thick strips and plant it just below the level of the cobblestones so that traffic would not kill it as fast. Maybe.

How about moss. There is a separate forum on moss on this site. You want something that will stay low. Grass doesn't make sense to me.

yeah, moss would be awesome, but i think it is too sunny, plus i didn't think moss stands up to much foot traffic...?

the only reason i thought maybe some kind of grass is because i have this image in my head of old cobblestone paths or streets that have grass growing in between... and i don't get the impression anyone is cutting it! in fact, i googled grass and "in between cobblestones" and it was quite hilarious what came up: loads of very romanticized references to the image...

do a google image search of GRASS BETWEEN COBBLESTONES and you'll see a bunch of the kind of image i am talking about. like look at this (scroll down just a tad)--
http://www.socketsite.com/3444%20Washington%20Backyard.jpg
how do you do that??

anyway, i'm totally open to not-grass, of course...

Here is a link that might be useful: image of grass between cobblestones

shoot, sorry. i did the link wrong. let me try again.

how do you get this kind of growth??

Here is a link that might be useful: {{gwi:288288}}

I have never seen anything like that "image of grass between cobblestones". Personally, it would drive me nuts to see that grass in between the stones in my courtyard! But, to each his own; maybe the grass in the photo is mowed like a lawn then manicured a bit to keep it in check. Reminds me of an ancient abandoned road.

I have moss growing between the stones in certain areas, and the courtyard is in full sun all day. It's green and durable unless there's a dry spell. Then it browns and can be lifted right up with the scuff of a shoe. I didn't plant the moss, it just appeared so unfortunately can't tell you the name of it. A moss covered walkway along side the garage is in shade mostly and when wet, the stones are slippery with it.

That's a neat photo. I have seen driveways done like that, with grass growing between concrete pavers that have a lattice pattern. Very pretty. But you have to water, mow, and fertilize, and I don't know if the grass would grow well in only 1/2 inch. If you really like the grass, you could go to Home Depot, buy a seven dollar bag of grass seed, throw it out there this fall and see what happens.

I live in a hot inland Southern California valley and I have moss that grows between the bricks in my patio every winter, but it dies back every summer. The patio is in full sun. It appears that some mosses grow in any conditions that are constantly moist. My neighbor gets it growing on his north facing asphalt roof shingles!

patio is in full sun and mainly flagstone--- want groundcover between stones - 1/2" - 3"tall - long flowering season - fairly fast grower - withstand foot traffic

Thyme is an option.