A number of nature centers in the Washington area offer wildflower walks during the spring. Rock Creek Center naturalists, for example, lead half a dozen walks on spring weekends. The first is scheduled for 2 to 4 p.m. tomorrow, rain or shine.

The center also furnishes free to the public a five-page list of local wildflowers and their blooming periods.

Here are some suggested wildflower guides to buy or borrow from the library. Use several; no one book offers everything.

Dana, Mrs. William Starr. How to Know the Wildflowers (Dover paperback, $6).

Newcomb, Lawrence. Newcomb's Wildflower Guide (Little, Brown, $12.95). Excellent key to finding flowers; good drawings.

Niering, William and Nancy Olmstead. The Audubon Society Field Guide to North American Wildflowers (Alfred Knopf, $12.50). Excellent photographs; detailed descriptions.

Peterson, Roger Tory and Margaret McKenny. A Field Guide to Wildflowers of Northeastern and North-Central North America (Houghton-Mifflin, paperback, $9.95). Fine drawings; detailed descriptions.

Reader's Digest, North American Wildlife (Reader's Digest Association, $20.50). Illustrated guide to 2,000 plants and animals. Larger than above books, but offers wealth of lore.

Stupka, Arthur. Wildflowers in Color (Harper & Row, $6.95). Covers southern Appalachian mountains. Photographs.

Watts, May T. Flower Finder (Nature Study Guild, Berkeley, Calif., $1.50). Pocket size.