blue flowers about a quarter inch across
mat-like spread

I'd say Veronica, there will be more than one species though.

Slender Speedwell (Veronica filiformis), it's a fairly common lawn weed in the Midwest.

ok, thanks...

I was going to add it to my Lists, but it doesn't appear to be in the DB. Is it listed under something else?

J: You should add your lovely photo's to the database! Creeping Speedwell (Veronica filiformis)

Just did, thanks.

Veronica persica is possible.

http://plants.usda.gov/java/pr...

http://www.thewildflowersociet...

http://www.naturespot.org.uk/s...

http://en.academic.ru/dic.nsf/...

http://www.plant-identificatio...

Or Veronica polita .. which looks closer

http://plants.usda.gov/java/pr...

http://www.flowersinisrael.com...

http://www.cas.vanderbilt.edu/...

http://flora.nhm-wien.ac.at/Se...

I doubt it's Veronica filiformis.

http://flora.nhm-wien.ac.at/Se...

http://flora.nhm-wien.ac.at/Se...

V. persica looks closer. Now I'll need to amend DB entry.

Check the length of the flower stalk.
This page gives a clue to the difference. It says V. persica "ID: Flowers solitary in leaf-axils, on stalks that are longer than their leaf but not twice as long. Flowers blue, the lowest petal often white. The similar V agrestis and V polita have flower-stalks shorter than their leaves and flowers less than 8 mm across. V filiformis has flower-stalks much longer than twice leaf length."

http://www.plant-identificatio...

I see I entered some pics from last year at the persica destination.

Given the flower stalk looks shorter than the leaf I would say it's polita. Look at the second photo on this site, it shows how much longer the stalk is on persica.

http://flora.nhm-wien.ac.at/Se...

I have cropped a part of your photo off jmorth, and blown it up. The stalk looks shorter than the leaf.

I think that may be an optical illusion Janet. The leaves are in a flat plain with the lens but the flowers are projecting up to make them look shorter. The flowers in the photo, at the link you gave look more than double the leaf length which would indicate V. filiformis, according to the description I posted. Not saying you are wrong, just that jmorth should do a personal inspection of the actually plant if possible, to be sure.

I know what you mean Jay, but compare the photo of filiformis and you can see a big difference in habit, leaves and length of stem.

http://flora.nhm-wien.ac.at/Se...

Physical inspection is a good idea!

Here's an Illinois plant website; I think your plant looks much like the picture they have for Veronica polita.

http://www.illinoiswildflowers...