Artists currently investigating the gap between nature and culture with a certain ironic shrug might take a careful look at the long career of San Francisco artist Ruth Asawa, which synthesizes her feeling for nature with Modernist ideas about abstraction and truth to materials. A small selection of her work since the 1950s provides a good introduction to the drawings, paintings, and the crocheted- or tied-wire sculptures for which she is best known. The crocheted-wire pieces, hanging in strands from the ceiling, suggest onions, plant bulbs, droplets, bubbles and fruits (the visible seeds and swelling shells suggesting botanical mother and child), while their open-weave construction invokes basketry and mathematical models. The tied-wire sculptures are flat, symmetrical dendritic wall-hanging pieces suggesting hexagonal sprays of foliage, root balls, fireworks, electrical discharges (as in Van de Graaf generators), stars and mandalas. The drawings “Pine Tree,” “Redwood Trees,” “Owl,” “Waves,” “Watermelon,” “Chrysanthemum” and “Imogen Cunningham” depict California’s natural landscape (including one of its eminent photographers) through a synthesis of traditional Eastern stylization and revolutionary Western abstraction.