Looks like a Sedum which would love more light. Hard to say which species, but with more light, should have more compact growth (& a better chance at getting a positive ID on it--could even be an xGraptosedum).

The bud and foliage reminds me of Bachelor's Button [Coneflower] ... but have never seen the yellow .... did a search on Bachelor's Button and it led me to Asteraceae ... which BB is in the family ... and there are pictures that seem similar to the one you show. ////// Or maybe SWEET SULTAN [is the flower fragrant?] Here is a link that might be useful: Asteraceae pictures

wantanamara, its just common blue grama, probably from seeds you sent me or else seeds I got at the History Museum. I keep trying to get new plants started, I love it. I visited the Museum today. They killed out all that mixed prairie grass growing on that hill of big rocks that I had admired so much, looks like they sprayed everything except the Muhly riverchonii. All the others were just dried up cut back dead grasses. I couldn't believe it! I plan to go back later on to see if they replace it with some other plants. No way its winter kill, that grass is too tough. In another area, they have large drifts of Little Bluestem and I don't know what kind it is but its extremely tall for a bluestem, the old seed heads from last year easily came up to my chest and the stalks are more than twice the height of the leaves, very blue, anywhere from powder blue to steel blue and has thinner leaves than other types. I found a few strays I saved from the weed whacker. You guys, thanks for the nice comments but except for the flame flowers all those plants are from seeds that came from Texas, its stuff grows wild in abundance on the roadsides. Roadsides are great for getting seeds, its a matter of "organization and selection" Wantanamara has great weeds on her property and its the common stuff I collect mostly, nursery's don't carry it because its considered common weeds. My eyeballs are constantly on the lookout for any interesting possibilities and they are everywhere. There is a large white prairie clover plant I just marked out last weekend for later seed gathering here. The thing looks like one of those perfect big white fireworks displays on the 4th of July. Btw, Oklahoma is third in its #'s of varieties native plants, just after Texas and California in the US. I read that this week online. I just ran across a teeny tiny form of stiff wiry grass, actually I think its a carex of some kind, cuter than a button with itty bitty brown seeds on top of those impossibly thin stems that stand up perfectly forming little upside down cone shaped plants that are about 4" tall. I have a little cluster started. This post was edited by TexasRanger10 on Thu, Jun 26, 14 at 3:40

Thank you mfyss. I have been trawling through Plectranthus images and some of them are tantalisingly close, but so far I haven't found it. They all seem to have serrated leaves (including Mona lavender which I never realised was in the coleus family, and Madagascar spurflower which I have been happily growing without knowing what it was). I have taken a look at P neochilus, which is another interesting plant, but not the right one. It will reveal itself eventually!