Nearly 30 years ago, I first walked through the remnant serpentine-soil grasslands of the Skyline Serpentine Prairie on a CNPS field trip. Steve Edwards extolled this western end of Reinhardt Redwood Regional Park not for its redwoods, but for its dense richness of coastal prairie grasses and wildflowers. This trip definitely hooked me on the prairie’s wildflowers, and I’ve weeded the prairie with years of restoration crews to preserve this unique flora.
With restoration crews on hold during the coronavirus pandemic, I returned to the Skyline Serpentine Prairie in mid-April to check on the early wildflower show in this Oakland hills habitat. The April blooms provided new wildflower sights for me, despite its relatively small area and a good-sized crowd in attendance.
An abundance of California poppies (Eschscholzia californica) climbed from the prairie’s east end at the horse arena west to the Richard C. Trudeau Training Center on Skyline Blvd. Nearest to the horse arena, California goldfields (Lasthenia californica) scattered bright yellow miniature sunflower shapes among the larger orange poppies. Uphill on the diagonal trail to the Trudeau Center, magenta red maids (Calandrinia menziesii) took the goldfields’ place alongside California poppies. Short-stem morning glory (Calystegia subacaulis ssp. subacaulis) and purple sanicle (Sanicula bipinnatifida) flowered in several places midway to the Trudeau Center.
The Skyline Serpentine Prairie retains coastal prairie plants but with an adaptation to its hostile soils. Two clarkia species, ruby chalice (Clarkia rubicunda) and the smaller, rarer Presidio clarkia (C. franciscana), spread a galaxy of pink in late spring, especially in wetter years. Tiburon buckwheat (Eriogonum luteolum var. caninum), yellow mariposa (Calochortus luteus), and native dandelion (Agoseris species) also bloom in May to June as the exotic annual grasses yellow and die.
In 2008, with advocacy and support from the Skyline Serpentine Prairie’s neighbors and our CNPS East Bay Chapter’s Conservation Committee, the East Bay Regional Park District began a long-term project “to restore the vitality and botanical diversity” of the prairie. The district hired biological consultants, including Golden Hour Restoration Institute and Creekside Science, to work with its stewardship staff on tree removal and timed mowing to improve the native flora’s recovery. Removal of trees and their duff increased of the population of Presidio clarkia, which has a world-wide range of only two counties. Other native wildflowers have benefitted from the restoration work, and spring displays can be breathtaking.
Learn more about the Skyline Serpentine Prairie and the ongoing restoration project on the East Bay Regional Park District’s Serpentine Prairie Resource Management pages, where you’ll find an explanation of the importance of the prairie, a guide to the wildflowers of the prairie, the prairie restoration plan, and annual reports on the progress of the restoration project.
– Janet Gawthrop, CNPS East Bay Field Trips Chair