The 11 abstract paintings, drawings, and prints by Wisconsin artist Robert Erickson at Gwenda Jay/Addington–part of a three-person exhibit titled “Earth & Sky”–are inspired by natural forms and have a mysterious presence. The drawing New Hope VIII looks a bit like a dark cliff or butte rising against a background suffused with horizontal lines, and the fuzzy gray areas at its edges create an aura that extends into the surrounding space. Other pieces have a peculiar weightlessness: In the painting New Hope III a line shaped like a reverse question mark trailing into three lines could just as well be read as the three lines fusing into one. One’s sense of up and down is even more confounded in the drawing New Hope VI, in which two thin lines rise from a circle that looks like a wreath or branching roots. Suggesting the ground while reaching toward the sky, this work also has an underwater feeling, recalling undersea plants that grow in all directions as if freed from gravity. For Erickson, nature seems less a matter of factual details than an almost ineffable spirit. At Gwenda Jay/Addington, 704 N. Wells, through December 21. Hours are 11 to 6 Tuesday through Saturday; 312-664-3406.