Rare Botanical Gems of Land Trust’s Missimer Snell Valley Wildflower Preserve

Since 2013, LTNC has been actively working to remove invasive species and restore native botanical resources at this stunning Land Trust permanent preserve. Located near Pope Valley, the Missimer Snell Valley Wildflower Preserve is known for its diversity and display of native wildflowers that occur in its regionally significant serpentine prairie habitat. Bay Area botanists have long recognized Missimer’s serpentine meadows as a gem of the regional flora of the North Coast Ranges. The original 240-acre Missimer Preserve was purchased by the Land Trust in 1999 with funds donated by Dale and Sue Missimer. In 2022, the Land Trust purchased 160 adjacent acres, so the Wildflower Preserve is now 400 acres.

The Preserve’s serpentine meadows are one of the most important botanical sites in both Napa County and the Bay region. “Serpentine” refers to the meadow’s soil type, which is inhospitable to many native plants but supports others that have evolved to cope with high heavy metal content and low nutrient levels. Several of these adapted native species are restricted to serpentine soils in northern California and found nowhere else.

Wildflower diversity and displays in these serpentine meadows were significantly diminished in recent years due to heavy invasion by an introduced plant from Europe called barbed goatgrass, along with a handful of other highly invasive species.

Working with CAL FIRE, LTNC has implemented several prescribed burns over the years that have successfully helped stave off invasive plants while adding significant wildfire risk mitigation and habitat restoration benefits. The focal meadow area, which was covered by goatgrass and other invasive species before the restoration began, is now dominated by native wildflowers once more.

The 290 native species on the preserve represent almost ¼ of all known Napa County native species. Highlights include royal larkspur (Delphinium variegatum) purple owl’s clover (Castilleja densiflora), smooth layia (Layia chrysanthemoides), and bird’s eye gilia (Gilia tricolor). Several species on the preserve are listed as rare, threatened, or endangered by the California Native Plant Society. Special status species found in the restoration area include Brewer’s milkvetch (Astragalus breweri), Purdy’s fritillary (Fritillaria puyrdyi) pictured above, Jepson’s navarretia (Navarretia jepsonii) and pink star tulip (Calochortus uniflorus).