“Neysa Grassi Rose Gatherer 2001-2011” presented the better part of a decade’s worth of labor-intensive oil paintings by this Philadelphia-based artist educated at the Pennsylvania Academy of Fine Arts in the early 1970s. Elegant and austere, the 19 works in the show offer potent impressions of the natural world, evoking water, foliage, earth and fire in subtly rendered textures, mottled colors and organic shapes. In some passages, Grassi mimetically reproduces the grain of wood or the pooling of liquid. Ranging in size from approximately 1 to 5 feet square, Grassi’s paintings are monumental yet delicate portals to a dimension in which the movements of nature commingle with polished corners and barely perceptible linear scrapings, which serve as tactical reminders of the artist’s hand.

Grassi’s serene palette (white scumbled over deep reds, blues or browns) and layered surfaces belie the elaborate explorations of her materials; the paintings often have a sculptural affect. The small Spirit Stone (2011) features burnished, bronzelike edges. These surround a dense, stratified picture plane whose depth and variegated satin finishes are evidence of Grassi’s preoccupation with building surfaces over time. By juxtaposing cool blues and lavenders with a yellow haze that leads to the molten edges, she conflates a range of chromatic and material temperatures, entrapping seemingly impossible registers in a single space. In the show’s catalogue, poet and critic Susan Stewart describes these images as “truly, erotically, embodied,” both in terms of their scale and their emergence as subjects with “repetitive, yet modulated, gestures.”

Larger canvases from 2011, such as Pleasant Lake and Poet’s Garden, self-consciously celebrate Grassi’s trademark multiple applications and modifications of pastel hues. Such works combine the romantic weight of land- and seascapes by J.M.W. Turner with the muted reflections featured in Monet’s Water Lilies. Feasts of soft colors at once intermingled and distinct, these canvases embed 19th-century influences within a baroque presentation, expressed by dark, ribbonlike bands that seep through and dance around the perimeters. Works on panel, such as Willow (2011), testify to Grassi’s range of thematic concerns. The image’s upper regions suggest an ethereal, whitewashed skyscape; this gives way in the bottom half to a more fluid, calligraphic abstraction, which seems almost linguistically expressive and reminiscent of Robert Motherwell.

Pendant to the large gallery of oil paintings was a smaller room focused on intimate works on paper also created mostly in the past decade. Though far less dense than her canvases, these monotypes, retouched with oil and gouache, provide further evidence of Grassi’s practice of revisiting and revising her restless surfaces, a compulsion that ultimately energizes and contains her enigmatic works. As a whole, this exhibition offered the opportunity for closer study of both the artist’s process and her celestial imaginary.

Photo: Neysa Grassi: Spirit Stone, 2011, oil on linen, 12 1⁄8 by 11 1⁄4 inches; at Locks.