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| Dichelostemma capitatum |
Mount Diablo is my second-favorite open space featuring fabulous flowers in the immediate Bay Area. Located an hour's drive due east of San Francisco in Contra Costa County, the state park has about 20,000 acres that form the nucleus of an impressive collection of protected lands totaling over 90,000 acres.
The mountain is 3,864 feet high and stands alone, making it one of the most recognized and recognizable geographic features in the Bay Area and adjacent portions of the Central Valley. The views from the summit are spectacular in all directions. An elfin forest grows at the summit, with trees only a little taller than your average male hiker.
Ceanothus cuneatus is a dominant species starting just above the middle of the moutain and reaching the summit. It grows thickly along the mountain's southern side and can produce a mass bloom in the spring that's breathtaking in appearance and almost overpowering in fragrance. A drive to the summit is heady and fragrant when the car windows are down.
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| Pinus sabiniana |
The interaction of the Pacific and North American plates along coastal California is responsible for Diablo, along with the rest of the Coast Ranges. The mountain continues to grow several millimeters per year. Tectonic forces are also responsible for a rich variety of seemingly incongruous rocks and minerals on the mountain.
Diablo lies at range border for quite a few plants, producing an unusually high species richness. Prominent plant communities include mixed oak woodland, chaparral, and grassland. There is year-round water flowing from the mountain, particularly in Mitchell Canyon.
I first encountered my absolute favorite pine tree species on Diablo,
Pinus sabiniana. The glaucous blue needles are instantly recognizable. It doesn't grow in dense stands, but as scattered individuals in chaparral and oak woodlands. And the cones! They're huge! The pine nuts are edible and were a source of food for the local Native Americans.
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| Ceanothus cuneatus |
I've hiked three trails so far on Diablo - the Globe Lily Trail in Mitchell Canyon along the northern flanks of the mountain, the North Peak Trail near the summit on the southern flank, and the short loop trail directly below the summit. Each trail was filled with rich and interesting plant communities. The road to the summit along the southern flank can produce stunning displays of
Eschscholzia californica and
Ceanothus cuneatus.
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| Calochortus pulchellus |
Diablo's signature flower is
Calochortus pulchellus, a
species of globe lily found only on Mount Diablo, primarily along the
Globe Lily Trail in Mitchell Canyon. That trail also leads through a
wonderful chaparral community dominated by
Salvia mellifera and
an almost pure white form of
Eriodictyon californicum.
Ericameria
linearifolia grows alongside the trails in Mitchell Canyon and I
wonder why that species isn't seen more in local gardens. I think it's
just as beautiful as the shrub daisy from South Africa everyone grows.
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| Fritillaria affinis |
I really enjoyed finding
Fritillaria affinis and
Ribes menziesii in a small
pocket of woodland along the North Peak Trail. Further along in a grassland area were several delicate patches of
Castilleja exserta, a favorite in the genus for me. There were even
Cardamine californica in bloom! This is one of our first spring flowers but it was still blooming at ~3500 feet! Near the start of the trail we found lots of
Arabis breweri on any boulder you stopped to investigate. We even found one of the rarest flowers in the Bay Area,
Streptanthus hispidus, growing in gravel next to the trail.
I'll be back next year (if I'm still living here!) to see what more interesting things I can find!
