One of the best places to experience a slice of Bay Area landscape as it might have looked before European settlement is San Mateo’s Edgewood County Park and Preserve. Offering a wide diversity of ecological zones, Edgewood is home to nearly 500 plant species and is best known for the native plants that thrive on its serpentine soils. Low levels of calcium and nitrogen, and high levels of magnesium and heavy metals, make this soil toxic to most plants, so exotic invaders aren’t able to gain a foothold. Threatened or endangered species found at Edgewood include San Mateo thornmint (Acanthomintha duttonii), Marin western flax (Hesperolinon congestum), and white-rayed pentachaeta (Pentachaeta bellidiflora), as well as the Bay checkerspot butterfly (Euphydryas editha bayensis). Flowers bloom from February through June, peaking in April and May, when the serpentine grassland is carpeted with wildflowers. Free public tours are led by Edgewood docents on Saturdays and Sundays from 10 a.m.-1 p.m., beginning in March. To find out where to meet, or to arrange group tours, see contact information below. If you want to help preserve the park and its unique resources, there are plenty of ways to get involved, including nonnative plant removal, trail patrols, docent training, and school outreach. The main entrance to Edgewood County Park and Preserve is on Edgewood Road, one mile east of I-280. For information call (866) GO-EDGEWOOD or log on to www.friendsofedgewood.org.