For people who like to browse, explore and ask a lot of questions, summer is the perfect time for gallery-going. The doldrums have set in, but the galleries are still there, and so are most of the dealers, willing -- in fact eager -- to show their wares. The variety of available work is also most visible during summer group shows.

Henri is still holding forth on the second floor of 1500 21st St. NW. The star of her current group is painter Tom Nakashima, who will be teaching at Catholic University next fall.

Nakashima makes allover pattern paintings, dividing the field vertically and then filling each section with a different pattern: thickly painted concentric zigzags, or circles, or triangles, all deliciously colored. In some more recent work, the artist seems to be experimenting -- thus far unsuccessfully -- with Matisse-like figures, floral shapes and collage.

Other works worth climbing the stairs to see are Tom Foolery's surrealistic boxes, Lester Van Winkle's funny sculpture and crazy 3D postcards by Harry Anderson, better known for his updated art nouveau lamps. Henri remains open through August. Sculpture at Gallery K

One of the most refreshing group shows in town at the moment focuses on sculpture, and it's at Gallery K, 2030 P St. NW. Eve Watt's ceramic depiction of a typical suburban Washington neighborhood swimming pool -- neighbors and all -- has great charm, as does "On the Beach," a sophisticated but whimsical wood sculpture by John Tinker of Albuquerque.

Several solar-powered sculptures by Allan Erdmann -- intriguing doodads for the science and engineering crowd -- keep the gallery filled with soft, space-age music that isn't half bad. The most puzzling work is by Pierre Keime, said to be a French folk artist, who makes strange narrative sculptures by molding tiny, toy-soldier-like figures from plastic, and then embedding groups of them in clear resin. His largest work -- in 16 parts -- deals with his interpretation (largely undecipherable) of the old American West, featuring soldiers and Indians.

In the back room, boxes by Peggy Shields and Andy Krieger, painted wood constructions by Ann Christopher and sculpture by Tom Schiefelbein stand out in this pleasant crowd. The show continues -- and continues to rotate -- through Sept. 12. 'eleven' at Touchstone

Touchstone Gallery, at 2130 P St. NW, has become one of the city's most endruing and varied co-ops, constantly upgrading its art and expanding its army of satisfied clients, many of whom didn't know what they wanted when they came in, but went out smiling. "Eleven for July," soon to be followed by "Eleven for August," is the summer format, and -- as always here -- it includes much work that is worth looking at, along with some that is not.

Starring is a new series of tinted photographs by Zinnia -- still-life images, featuring parts of a tree, or a bit of paper, or some cloth, all nestled in a leafy forest floor. By adding color to each photograph, Zinnia has altered the allover appearance of the scenes, making them mysterious and in some cases no longer recognizable. Rima Schulkind, ceramic artist extraordinaire, has also taken a wholly new tack -- and a promising one -- in a series of handsome, pit-fired sculptural forms -- tall, cylindrical containers, some incorporating the convoluted branches of a wry bush called Larry Lauder's Walking Stick. Some small maquettes for sculpture look promising, but the new wall plaques do not.

A charming three-part painting of a parade in Leesburg by Vinton Pickens and work by Morella Belshe, Harriet Rosenbaum, Gretchen Friend-Jones, Irene Zweig, Judith Turim and newcomer Kit-Keung Kan offer a broad range of other satisfying possibilities. Basketry at Greenwood

One gallery that gets too little attention from the art crowd -- though well-attended by the crafts crowd -- is Greenwood Gallery, 2014 P St. NW. The current show, an invitational basketry exhibition, is typical: not quite up to Renwick standards, but, nonetheless, an ambitious effort of high quality. Basketry is booming these days, both traditional forms in split white oak from Mississippi and more sculptural forms turned out by highly inventive artists who use basketry as a mode of expression. The standout in the latter category here is Glen Echo Park's own Jill Romanoke, who devises wonderful sculptural forms from mere grapevines and spring grasses.

Upstairs, a broad range of interesting work by artist-craftspeople is constantly on view. Notable among the current group are Jean Thickens Francis, Liz Kegloe and Michael Olijynk, who makes small but striking sculptural constructions from handmade paper. The basketry show continues through Aug. 28. Melchert Drawings

Today, from 11 to 2 at Fendrick Gallery, 3050 M St. NW, Washington will have its first chance to see the work of artist James Melchert, better known, since 1977, as director of the Visual Arts program at the National Endowment for the Arts. Melchert leaves that post to return to teaching at the University of California, Berkeley, next week.

His show is entitled "The Teotihuacan (Sun Pyramid) Series: Drawings as Re-enactments" -- Melchert's expressed perception of the structure and inherent energies emanating from that great pyramid outside Mexico City, which he climbed last fall. Each drawing is a variation on the same abstract schema -- a sort of shorthand symbol for the stepped pyramid -- that looks like a character in oriental calligraphy. Through energetic layering of this image with another squared image (representing the layered mass of the pyramid itself), Melchert does actually succeed in recreating his own excitement about the experience, both through the exuberance of the drawing and the brilliance of the colors, which seem to allude to blood sacrifice. Melchert will show again at Diane Brown next year.