"Geo-Morph: New Currents in Geometric and Biomorphic Abstraction" is the rather forbidding title of a show of works by mostly Northern California artists at the Pence Gallery in Davis.

While you might expect the show to be on the dry side, in reality it is a lush and vibrant display of works on paper assembled by art critic David Roth, whose Web site Squarecylinder.com, keeps track of serious contemporary art exhibits here and in the Bay Area.

The show reflects two trends in abstract art. Simply put, geometric abstraction focuses on forms such as squares, triangles and circles, while biomorphic abstraction employs organic forms drawn from the natural and supernatural realms. When one thinks of geometric abstraction, Piet Mondrian comes to mind. Prominent practitioners of biomorphic abstraction include Vassily Kandinsky. Mondrian dealt with pure, reductive forms, while Kandinsky created synthetic, surreal forms. Both expressed the spiritual in their own distinctive ways.

One thing that "Geo-Morph" makes clear, however, is that the 13 contemporary artists in it are not so pure as Mondrian and Kandinsky. Many of the works in the show are hybrids of both tendencies, though often with one or the other dominating. For the purposes of the show, the distinction between the two types of abstraction gives you a key but does not open the door. The artists themselves do that swinging their spirits wide open.

Joan Moment's "Gridlock" and "Jumping Jumble" are insouciant arrangements of squares and hexagons that set up a geometric dance that delights the eye. Though the forms are regular, they are richly layered so they have smears, drips and ghost images that play their part in the composition of the field of rectilinear markings.

Ellen Van Fleet's three-dimensional paper collage "Stripe #3" is geometric in its repetition of black stripes on a warm, brown ground and yet it feels more like a creature, an animate form that dazzles the eye with its undulations and swellings.

More purely geometric are Hearne Pardee's arrangements of imperfect geometric forms attached to painted paper with clear push pins that give a spectral, three-dimensional appearance to the works. Geometry too plays a strong role in the architectural fantasies of Jeff Konigsberg and Robin Hill's small skyline made of steel linotype characters that form an urban silhouette against a window in the gallery.

Val Britton's "Beginning Anywhere" is an ambitiously scaled wall piece, with a lacy cutout section that blends geometric and biormorphic forms of imposing sweep and grandeur. Hybrid, too, and fascinatingly so, is Anna Fidler's "Maypole" a group of low-relief, three-dimensional figures made up of topographical forms that suggest alluvial planes in fantasy landscapes. Leslie Shows combines geometric and biomorphic abstraction in her quirky, brooding organic forms that hover over a collage of candy wrappers and food labels.

Darren Waterston's "Fugue," a dark and brooding biomorphic abstraction, bristles with electricity and bird and insectlike forms appear in shadowy markings.  Sid Garrison's "March 24, 2008" is a lush biomorphic abstraction with simple forms delineated in white on an intense blue that calls up associations with the blue used in blueprints.

Julia Couzens proves to be the most versatile and searching artist in the show with 13 books of drawings, paintings and collages that have the verve of a rough-edged Mondrian and the elegance of Matisse. They are worth a trip to the show on their own.

From Peter Voulkos' muscular abstraction made of painted and torn paper to Lisa Marasso's looping wall piece of cardboard and glitter, this is a show that despite its intellectual underpinnings sings visually.