It's more than just a variety of zinnia :9 Turns out I've been doing this for awhile, just didn't know there was a term for it. Basically several species of leaf/head vegetable can be harvested by cutting 3/4" to 1" above the soil, and allowing new leaves/heads to grow out from the stump. You'll have to continue to water the roots and put up with a stump, but in a few weeks you have more edibles without going through seed starting.
Above is a shot of my lettuce pot about a month ago. I harvested the lettuce from it about three weeks ago, and being the lazy butt that I am I just left the stumps there rather than re-potting it with new yummies.
Fast track to this last weekend and you can see that one lettuce stump is now producing three new heads for my dinner salad. The only drawbacks to this method are putting up with a less than purty stump for a few weeks, and the new leaves/head that grow back do not grow as large as the original.
This method will also work for kale. One stump is regenerating one...uh...clump of kale, and the other is sprouting two. These are growing very quickly and the leaves look more tender than the original plant...
Spinach, broccoli and cauliflower are supposed to regrow like this also although I haven't tried it yet.