Art gallery exhibitions: Donald Martiny; Emily and Will Brown; April Saul

Donald Martiny's paintings - lush gestures of paint on aluminum supports - function almost as bas-reliefs formed from paint.

I've seen them in various places over the last few years, but his first solo show at Pentimenti Gallery offered me my first opportunity to see many of them together in person. They're remarkable in many ways, not least for the individuality each work embodies while simultaneously affirming Martiny's signature style. They also look terrific in this gallery, which has done well to turn over the entire space to Martiny and to leave lots of space between these assertive works. They deserve it. Each one is an experience.

Martiny makes his paintings on the floor, using brushes, brooms, and even his hands to push his paint, a viscous mix of pigment and polymer, and his physical interactions are clearly evident in all of his paintings. But as sweeping and physically demanding as Martiny's gestures can seem, they can just as easily suggest a much enlarged gesture from an expressionistic painting on canvas, a flick of the wrist (and brush) isolated and magnified.

Willem de Kooning's landscape-inspired paintings of the 1960s and '70s strike me as touchstones for several of Martiny's recent works. Yabaâna (2016), a thrusting, wavelike shape of white paint thinly streaked with yellow, green, and pink, brings to mind de Kooning's vigorous brushwork and color palette, as does Gafat (2016), an indeterminate form of fleshy peach and green intersected by bold strokes of royal blue and cadmium orange that could have stepped out of de Kooning's Two Figures in a Landscape from 1967 (it didn't).

But Martiny's monochromatic pieces are as emphatic as ever. Tuu (2016), an immense "dab" of deep brownish violet, is as self-possessed a painting as you can imagine, defying its dramatically plain-Jane color. It stops you like a period at the end of a sentence. You have to admire it.

In most of these works, Martiny has moved away from forms that immediately evoke other forms - I've seen paintings of his shaped like commas, for instance. And these new, less referential shapes match up nicely with his more nuanced palette.

Through April 23. Pentimenti Gallery, 145 N. Second St. Hours: 11 a.m. to 5 p.m. Wednesdays through Fridays; noon to 5 p.m. Saturdays. Information: 215-625-9990 or www.pentimenti.com.

Here's an exhibition that may qualify as the most interesting undertaking yet by the Pennsylvania Academy of the Fine Arts Alumni Gallery, which, as indicated by its name, exhibits only works by its graduates.

"Brown & Brown" pairs the works of Emily (Scott) Brown and Will Brown, who met as students in PAFA's B.F.A. program (coordinated with the University of Pennsylvania) and married shortly after.

Emily Brown's plein-air ink wash paintings on paper are well-known in Philadelphia and elsewhere and have been exhibited in Philadelphia at Gallery Joe numerous times, in solo and group exhibitions. Will Brown is a self-taught photographer who has had a long career photographing art, artifacts, and architectural spaces. His early-1970s photographs of Philadelphia storefronts were rediscovered in 2009 and shown as part of an exhibition at the Philadelphia Museum of Art and more recently in a solo show at Laurence Miller Gallery, New York. Of late, he's been photographing horse troughs and springs in Philadelphia, as well as houses in Maine.

But aside from living together in Philadelphia and Maine, and working on occasional projects together, the two have never collaborated on artworks and have maintained separate practices.

Of course, their exhibition, which marks the first time they've shown their work together, reveals affinities, as it must have intended to do. We learn that both Browns are nature lovers, share a passion for history, and are drawn to the unexpected or overlooked. I found the similarities between Emily Brown's ink wash paintings of tree branches and Will Brown's recent photographs of troughs and springs in Fairmount Park downright eerie.

Through April 24. PAFA Alumni Gallery, Historic Landmark Building, 118 N. Broad St. Hours: 10 a.m. to 5 p.m. Tuesdays, Thursdays, and Fridays; 10 a.m. to 9 p.m. Wednesdays; 11 a.m. to 5 p.m. Saturdays and Sundays. Information: 215-972-7600 or www.pafa.org/alumni-gallery.

The final day of April Saul's two-gallery exhibition at Swarthmore College arrives Sunday.

In the college's List Gallery, Saul, a Pulitzer Prize-winning photojournalist who worked for the Inquirer, is showing photographs of Camden as part of a series chronicling the lives of its residents. On view in its McCabe Library are selections from several of her extended photo essays - "Our American Family," capturing the challenges faced by diverse families; "Kids, Guns, and Violence: A Deadly Toll"; and "Between Genders," documenting the experiences of a Navy veteran who underwent gender-reassignment surgery at 77.

I walked through these two shows riveted not only by Saul's obvious talent as a photographer and the honesty of her pictures (I'm still trying to picture Saul in that derelict bedroom, her lens trained on two crack addicts lighting up), but by the incredible trust she must have inspired in her subjects.

Through April 3. List Gallery and McCabe Library atrium gallery, Swarthmore College, 500 College Ave., Swarthmore. Hours: Noon to 5 p.m. Tuesdays through Sundays. 610-328-7811 or www.swarthmore.edu.