Bloomsdale spinach?

Last weekend I was at the Saturday Santa Monica (Ca.) Farmer's Market, which features all-organic produce (and flowers, and meats, and shellfish, and nuts, and more, and more). We were buying some fingerling potatoes, and the vendor handed us each a leaf of what she described as "sweet spinach" (and, which the sign said, has no or low tannins). It was heavenly, and for the rest of the weekend I kicked myself at having not bought a bag full of it. I saw the same vendor at the Sunday Santa Monica Farmer's Market, but alas they'd sold out of the sweet spinach. I asked about its season, and was told that it's short (in other words, "now" in Southern California). Now I'm back in Chicago and I want some more of this spinach!

A Google search turns up that I was probably tasting "Bloomsdale Spinach." Has anyone seen this at any of our local farmer's markets or grocery stores?