Chalcedon Checkerspot
Euphydryas chalcedona
CA Special Concern
California Species of Special Concern
Medium butterfly with bold red-orange and cream checkerboard pattern. Host plant-specific to paintbrush and owl's clover. Locally variable populations indicate specialized habitat requirements in Bay Area foothills.
Plants that support Chalcedon Checkerspot
54 plants
American Cow-parsnip
Heracleum maximum
perennial herb
Adult nectar source; flight period Jun-Aug in California
Bird's-eye Gilia
Gilia tricolor subsp. tricolor
annual
Adult butterfly nectar foraging on wildflowers
Blue Field Gilia
Gilia capitata
annual
Regional butterfly utilizing wildflower blooms during flight season
Brewer's Ragwort
Packera breweri
perennial herb
Larvae feed on foliage in spring; critical host plant for caterpillar development
Butterfly Mariposa Lily
Calochortus venustus
geophyte
Larvae feed on bulb leaves in spring during development
California Ash
Fraxinus dipetala
tree
Larvae feed on ash foliage in spring; host plant for this California endemic butterfly
California Chia
Salvia columbariae
annual
Larval host plant for caterpillar development in spring
California Coffeeberry
Frangula californica
shrub
Larval host plant for this checkerspot butterfly
California Goldenrod
Solidago velutina ssp. californica
perennial herb
Adult nectar source during flight period Jul-Oct
California Lilac (Blue Blossom)
Ceanothus thyrsiflorus
shrub
Caterpillars feed on spring growth; multiple broods possible
California Prickly Phlox
Linanthus californicus
perennial herb
caterpillars feed on plant foliage in spring after overwinter diapause
California Wild Rose
Rosa californica
shrub
Important larval host; caterpillars feed May-Jul
California Yampah
Perideridia californica
perennial herb
Caterpillars feed on Apiaceae hosts; univoltine populations emerge Apr-Jun
California goldfields
Lasthenia californica
annual
Larval food plant supporting caterpillar development in spring
California pearly everlasting
Pseudognaphalium californicum
perennial herb
larvae feed on foliage in spring; critical host plant for caterpillar development
Canyon Dudleya
Dudleya cymosa
succulent
Larvae feed on Dudleya foliage in spring; critical host plant in canyon habitats
Chamise
Adenostoma fasciculatum
shrub
Caterpillars feed on chamise leaves; adults emerge mid-summer
Chinese Houses
Collinsia heterophylla
annual
Primary larval host plant; caterpillars feed on foliage in spring
Coast Wallflower
Erysimum capitatum
perennial herb
Critical host plant for early season larvae development
Common Fiddleneck
Amsinckia menziesii
annual
Early-season larval host plant, critical for first brood
Common Woolly Sunflower
Eriophyllum lanatum var. achilleoides
perennial herb
Early spring larval development, critical host plant
Deerbrush
Ceanothus integerrimus
perennial herb
Early-season caterpillar host plant in California foothills
Dense-flower Indian Paintbrush
Castilleja densiflora subsp. Densiflora
annual
Adult nectar foraging in spring
Distant Phacelia
Phacelia distans
annual
Host plant for caterpillars in spring through early summer
Dotseed Plantain
Plantago erecta
annual
Caterpillars feed on Plantago erecta leaves in early spring after host plant emergence
Exserted Indian Paintbrush
Castilleja exserta subsp. exserta
annual
host plant for spring broods
Foothill Penstemon
Penstemon heterophyllus
perennial herb
Larval host plant; caterpillars feed on foliage in spring
Glandular Layia
Layia glandulosa
perennial herb
Larval food plant supporting population in coastal California
Indian Warrior
Pedicularis densiflora
perennial herb
Important larval host; caterpillars feed on foliage during spring development
Interior Goldenbush
Ericameria linearifolia
shrub
Critical larval food plant; caterpillars feed on foliage in spring
Ithuriel's Spear
Triteleia laxa
geophyte
Spring blooms provide early season nectar Apr-Jun
Mariposa Lily (Yellow)
Calochortus luteus
geophyte
Spring/early summer visitor to lily flowers
Mountain Coyote Mint
Monardella odoratissima
perennial herb
Larval host plant; caterpillar feeding March-May before pupation
Narrowleaf mule ears
Wyethia angustifolia
perennial herb
Early season larval host; caterpillars feed on plant foliage
Ninebark
Physocarpus capitatus
shrub
Larval host plant; caterpillars feed on ninebark foliage
Oregon Bigroot
Marah oregana
vine
Important larval host plant for checkerspot populations
Popcorn-flower
Plagiobothrys nothofulvus
annual
Spring host plant for developing caterpillars
Rayless Arnica
Arnica discoidea
perennial herb
Caterpillars feed on arnica leaves during spring-early summer development
Ruby Chalice Clarkia
Clarkia rubicunda
annual
Nectar source for adult butterflies
Silver bush lupine
Lupinus albifrons
shrub
Primary larval host plant for early spring broods
Sonoma Mountain Pride
Penstemon newberryi var. sonomensis
perennial herb
Caterpillars feed on plant foliage in spring, critical host plant for population persistence
Sticky Monkey Flower
Diplacus aurantiacus
shrub
Larval host plant for caterpillars; adults nectar on flowers
Texas Indian Paintbrush
Castilleja foliolosa
perennial herb
Larvae feed on plant foliage in spring after host plant emergence
Vervain
Verbena lasiostachys var. scabrida
perennial herb
Early season larval host; caterpillars feed on foliage in spring months
Whitehead Mule-ears
Wyethia helenioides
perennial herb
Larval host plant; caterpillars feed on plant foliage during spring emergence
Woodland Sunflower*
Layia gaillardioides
annual
Caterpillars utilize foliage as early season host plant
Yellow Bush Penstemon
Keckiella antirrhinoides
perennial herb
Critical larval food plant for caterpillars in spring; host plant utilization subspecies-dependent
Yerba Santa
Eriodictyon californicum
shrub
Host plant for caterpillars; critical for larval development