Gladys Nilsson

Through March 14. Garth Greenan Gallery, 545 West 20th Street, Manhattan; 212-929-1351, garthgreenan.com.

Through April 18. Matthew Marks Gallery, 523 West 24th Street, Manhattan; 212-243-0200, matthewmarks.com.

If I had just one word to sum up the art of Gladys Nilsson, who’s been painting for more than 50 years, it would be “exuberant.” Her work contains relentless energy and, by extension, optimism. Abounding with wacky figures of different sizes cavorting and contorting in brightly colored scenes, her oeuvre feels like a celebration of being alive.

Ms. Nilsson got her start in the mid-1960s, when she and five fellow graduates of the School of the Art Institute of Chicago began exhibiting together as the Hairy Who. They were part of a larger movement, the Chicago Imagists, whose graphic, irreverent art drew on pop culture and reflected an absurdist sense of humor and an often unglamorous interest in the body.

In the past decade, the group started to receive its due outside its home city, but individual members remain underappreciated, especially (and not surprisingly) the women. Ms. Nilsson’s current doubleheader, “Honk! Fifty Years of Painting,” at Matthew Marks Gallery, which is showing work made from 1963 to 1980, and Garth Greenan Gallery, where recent paintings are on view, is the largest presentation of her art to date, accompanied by the publication of her most comprehensive catalog. It is in no way large enough and doesn’t include any watercolors on paper, her primary medium. But it’s a start.