Joan Nelson's little square paintings on wood look like swatches cut from an Old Master landscape in a state of genteel decay. One of these untitled works offers a glimpse of abraded orangy sky, framed by fern-like reddish-brown leaves and the varnished-brown silhouettes of trees. In another, a porous brown tree on a celedon background looks like a pickled Ming Dynasty scroll painting.
There's a Delft blue sky with billowy clouds and two pairs of slender, giraffe-like 17th-Century Dutch landscape trees. And a misty brown autumnal tree bowed against a scrubbed greenish sky that could be a fragment from a late work by George Inness. Nelson also manipulates her oil and wax media to suggest lovely fungus growths or a richly linear engraving quality or a curious decal effect. It's all quite seductive in a small package. (Michael Kohn Gallery, 313 N. Robertson Blvd., to Jan. 4.)