Wildflower Mount Diablo Brewer’s Ragwort Scientific Name: Packera breweri Family: Asteraceae (Sunflower Family) Blooms: Apr-May Color: Yellow-Orange Perennial herb Native, endemic to California Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Steve Beatty

Most Excellent Spring Hike by Steve Smith Camels, Sunsets, and Buckeyes March 28, 2025 Steve Smith It is wildflower season on Mount Diablo and the hike of the month will explore some of our best single-track trails with some explosions of color. This hike can be modified to begin from just about any trail entrance, this version begins from North Gate Road where Burma Road crosses over, there are a dozen or so parking spaces in this area. You can just as easily begin from Castle Rock Park in Walnut Creek or Macedo Ranch in Alamo. The hike here is 5.7 miles and 1,000 feet of climbing...but you should allow lots of time to enjoy the beauty along these trails. Of course a nice sunny day is best for maximum color impact. Don't wait too long though, as the non-native grasses grow taller and taller, the poppies and other low-growing flowers tend to get swallowed up. North Gate Road is well-known for Mount Diablo's version of a superbloom, and right now the Poppies and Lupine are abundant and spectacular. Park where Burma Road crosses North Gate and head uphill on Burma, making your first left on Camel Rock Trail. You are going to explore this trail for 1.6 miles and will find many lovely flowers as well as several mini-waterfalls and fabulous rock outcrops along the way. Arroyo Lupines line the hillsides but you'll also find Fremont Star Lily, Blue Dicks, Blue Witch, and of course fields of Poppies. At trail's end you will cross back over North Gate and down Little Pine Creek trail. Make your first right and begin your climb up Falcon Road. This area is beginning to pop with color, take note of the varying colors of green as the Oak trees and Buckeyes continue to leaf out. You may be greeted with some pops of yellow Mule Ears along the way. Keep your eye out as you get closer to the top for the Wood Spirit guarding the trail. Turn right on Sunset Trail ensuring you learn a little about our Peregrine Falcons at the interpretive panel...Castle Rock is off limits this time of year for nesting. Sunset Trail is a lovely winding path down the hillside with lots of "smalls", flowers less than the size of a dime. However, keep an eye out for our iconic and endemic Mount Diablo Globe Lily...they are just starting to pop up throughout the park and along here in early April. Once you reach trail's end, hang a left on Stage Road. This is the original stagecoach route which once brought visitors from the train station in Martinez up to the Mountain House Hotel in the late 19th century. Beware this time of year as you will be crossing Pine Creek half a dozen times or more as you soak up the sounds (and perhaps the water) of a babbling brook and the lush riparian corridor. You will be traveling this relatively flat trail for about a mile before you veer to the left as Stage Road begins to climb back up the hill. Look out for carpets of Fiddlenecks and Blue Dicks before making a left on Buckeye Trail. Here you are treated to lush grasses and some small waterfalls...keep your eye out on the right for our showiest of flowers, Mule Ears. As you begin to glimpse the hills beyond you should start seeing hillsides of Poppies, particularly the area above and below the North Gate Road washout. Arroyo Lupine are abundant as well in addition to Mustard and Wild Radish. Continue on this lovely trail for a total of 1.2 miles until you reach Burma Road again, a quick right will bring you back to your car. C heck out our Wildflower Bloom Report and take it along with you to see how many you can find along the way! Wood Spirit Fiddleneck Mule Ears Arroyo Lupine Camels-Buckeyes BACK TO LIST

Turkey Vulture Diurnal Birds of Prey Turkey Vulture Carthartes aura All Year Diurnal Birds of Prey Daniel Fitzgerald Found in open woodlands, or in open country near cliffs or forested areas. In-flight, comparatively long tail and two-toned coloration to underside of wings distinguish this species. Featherless head is red. When flying, wings are held in a slightly upward position, creating a ‘V-shaped’ or dihedral appearance. Typically nests in the base of hollow trees or tree stumps, or on cave floors or cliff ledges. Generally no nest materials are used. Feeds on a diverse array of carrion of both wild and domestic origin, with mammals being most common.

Rufous Hummingbird Hummingbirds Rufous Hummingbird Selasphorus rufus Migrating Hummingbirds Daniel Fitzgerald The adult male has a rufous back and tail and bright orange-red throat. The adult female and immature birds have a green back and dull rufous sides and at the base of the tail.

Grassland American Crow Corvus brachyrhynchos American Kestrel Falco sparverius American Pipit Anthus rubescens American Robin Turdus migratorius Band-tailed Pigeon Patagioenas fasciata Barn Owl Tyto alba Barn Swallow Hirundo rustica Black Phoebe Sayornis nigricans Brewer's Blackbird Euphagus cyanocephalus Brown-headed Cowbird Molothrus ater Bullok's Oriole Icterus bullockii Burrowing Owl Athene cunicularia Calliope Hummingbird Selasphorus calliope Cedar Waxwing Bombycilla cedrorum Chipping Sparrow Spizella passerina Cliff Swallow Petrochelidon pyrrhonota Common Raven Corvus corax Cooper's Hawk Accipiter copperii Eurasian Collared-Dove Streptopelia decaocto European Starling Sturnus vulgaris Fox Sparrow Passerella iliaca Gambel's White-crowned Sparrow Zonotrichia leucophrys gambelii Golden Eagle Aquila chrysaetos Golden-crowned Sparrow Zonotrichia atricapilla Great Horned Owl Bubo virginianus Horned Lark Eremophila alpestris House Finch Haemorhous mexicanus House Sparrow Passer domesticus Killdeer Charadrius vociferus Lark Sparrow Chondestes grammacus Loggerhead Shrike Lanius ludovicianus Mourning Dove Zenaida macroura Northern Harrier Circus hudsonius Northern Mockingbird Mimus polyglottos Phainopepla Phainopepla nitens Purple Finch Haemorhous purpureus Red-shouldered Hawk Buteo lineatus Red-tailed Hawk Buteo jamaicensis Red-winged Blackbird Agelaius phoeniceus Rock Pigeon Columba livia Rock Wren Salpinctes obsoletus Savannah Sparrow Passerculus sandwichensis Say's Phoebe Sayornis saya Sharp-shinned Hawk Accipiter striatus Song Sparrow Melospiza melodia Swainson's Thrush Catharus minimus Tree Swallow Tachycineta bicolor Violet-green Swallow Tachycineta thalassina Western Bluebird Sialia mexicana Western Kingbird Tyrannus verticalis Western Meadowlark Sturnella neglecta White-crowned Sparrow Zonotrichia leucophrys White-tailed Kite Elanus leucurus Wild Turkey Meleagris gallopavo

Mournful Duskywing Erynnis tristis Hesperiidae Skippers Flies January to October Host Plant Oak Nectar Plant Daniel Fitzgerald Male Michael Marchiano Male Daniel Fitzgerald Underwing

Boisduval's Blue Icaricia icariodes Lycaenidae Blues, Coppers, Hairstreaks Flies March to July Host Plant Lupine Nectar Plant Michael Marchiano Male Daniel Fitzgerald Underwing Ken-ichi Ueda Female

Wildflower Mount Diablo Rayless Fleabane Scientific Name: Erigeron petrophilus Family: Asteraceae (Sunflower Family) Blooms: June Color: Yellow-Orange Perennial herb Native Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Daniel Fitzgerald

Early Spring Wildflowers by Kevin Hintsa January 1, 1999 Mount Diablo Manzanita | Kevin Hintsa The winter rains and increasing daylight of early spring triggers a spring bloom for many of Mount Diablo's native wildflowers. The exact timing and quantity of blooming wildflowers will vary greatly year to year as it is controlled by a number of environmental factors. By late February there are a number of flowers to view, especially in the chaparral and at low elevation grassy hilltops. The following include most of the more striking species that one might find in the first three months of the calendar year. Bear Brush (Garrya fremontii ) starts off the new year in a bizarre manner by blooming in early January at the summit of Mount Diablo. This uncommon evergreen shrub, resembling the evergreen oaks in both leave and flowers, produces two inch long pale lavender catkins on the male shrubs. Blooming may be triggered by the increasing daylight as it often blooms in icy conditions. The more common Coast Silk-tassel (Garrya elliptical is easily found between Curry Point and Sycamore Canyon in February and March). Manzanita (Arctostaphylos sp. ) is perhaps the star attraction of December to March. These evergreen shrubs with red bark fill the chaparral (and a few wooded slopes) with delicate white to pink tiny bell-like flowers that attract a great number of insects and the occasional hummingbird. The Mount Diablo Manzanita (Arctostaphylos auriculata ) grows only around Mount Diablo and has the pinkest blossoms of the mountain's manzanita. It is easily seen around Wall Ridge, Live Oak Campground and also between Curry and Knobcone Point. Another early bloomer is Chaparral Currant (Ribes malvaceum ). This deciduous shrub often begins blooming in late December at lower elevations, finishing at the summit around early May. The flowers are pink and are quite striking when seen in mass. It is easily seen around Knobcone Point and along Summit Road. The similar Gooseberry differs in having thorns and smaller flowers. Mitchell Canyon and the summit area are good places to look for it. Warrior's Plume is a semi-parasitic herbaceous plant of chaparral-pine areas. The red green leaves are a pleasant sight in early March along Wall Ridge or Curry to Knobcone Point. It blooms in April at the summit. The newly opened leaves are pure red in this and many other species as a protection against ultra-violet light. Members of the Mustard family are well known early bloomers. Milk Maids (Cardamine californica ) is very common just about everywhere on Mount Diablo, often occurring in heavily shaded forests. Its simple white flowers can be common by mid-February at low elevations, finishing at the Fire Interpretive Trail in May. Our state flower, the California Poppy blooms nearly year round, mostly March to October on Mount Diablo. Its lacy gray-green leaves and golden yellow to orange flowers are well known to most Californians. It is generally found in the grasslands below 3500 feet. Check North Gate Road in mid-April to early May for peak mass bloom. Buck Brush (Ceanothus cuneatus ) is an evergreen shrub that is fire dependent, as it gets crowded out in older stands of chaparral. Its mass of white blossoms (smelling like popcorn) starts in early February along lower South Gate Road, finishing in May at the Fire Interpretive Trail. Jim Brush (Ceanothus oliganthus ) is another of the so-called California Lilacsi. It has powder blue blossoms and blooms from late March through May, more commonly on the north side of the mountain. Very pleasing to the eye in early March is Johnny-Jump-Up (Viola-pedunculata ). These are golden yellow with black markings and have a striking reddish brown underside. Look for it a Curry Point. Much smaller and more widespread on the mountain is the similar looking Mountain Voilet (Viola purpurea ), blooming March to May. It is fairly common in the area around the Summit. Brewer's Rock Cress (Arabis Breweri ) is found on rock outcrops at 1200 feet to the summit. Its small pale green leaves grow in rock crevices and it has beautiful pink to purple flowers (that later form curved seed pods). The summit area is the best site to study this species, but also look for it at the Falls Trail in Donner Canyon. Mosquito-bills (Dodecatheon hendersonii ) is the common species of Shooting Star around Mount Diablo. The nodding pink flowers are quite adorable, especially when in mass. The leaves are simple and basal. Look for it from mid February through April, especially in Mitchell Canyon where it is very common. Grand Hound's-Tongue is a widespread member of the forget-me-not family on Mount Diablo, most found in wooded areas of light shade. It has foot tall flower stalks with powder blue to violet flowers. It usually is well in bloom by March 1 at lower elevations, and finishes in late April along the Fire Interpretive Trail. Brewer's rockcress | Kevin-Hintsa Warrior's plume | Mike Woodring Milk Maids | Kevin Hintsa California Poppy BACK TO LIST

American Lady Vanessa virginiensis Nymphalidae Brushfoots Flies All year Host Plant Everlasting Nectar Plant Daniel Fitzgerald Male Underwing Kevin Hinsta Female

Geologic Guide to the Falls Trail Loop by Ken Lavin and Karen Synowiec Mountain News, Fall 1996 September 1, 1996 Falls Trail | Paul Salemme The Falls Trail loop is one of Mount Diablo's most popular hikes. In addition to impressive cascades and wildflower displays, the walk provides an introduction to the fascinating geology of Mount Diablo. The loop is six miles long, with a total elevation gain of 1,300 feet. Portions of the route are rugged, so it is advisable to wear lug soled boots. The trail head is at the end of the Regency Drive cul-de-sac in Clayton. The first portion of the trail follows Donner Canyon Road south along Donner Creek. Although Donner Canyon Road is wide and well-graded, this first part of the hike is often challenging after a heavy rain, because of the peculiar geology underlying the lower portion of Donner Canyon. These rocks belong to the 140 million year old Knoxville Formation, part of the Great Valley Sequence. These Mesozoic (Dinosaur) age rocks are composed of material weathered off the ancestral Sierra Nevada mountains and deposited into an ancient sea. The Knoxville Formation includes units of mudstone that are rich in clay minerals. Clay is extremely porous and readily incorporates water between flat, platy grains. Although porous, clay is nearly impermeable, and therein lies the problem. The "fat" clusters of water molecules cannot squeeze through tiny pore spaces between the clay grains nor overcome the electrostatic attraction exerted by the platelets. The water stays trapped in the pore spaces. The applied result of these hydrogeologic properties is a muddy goop that sticks to the bottom of your boots as you slog up the trail. About one mile up Donner Canyon, you will encounter the old Donner Cabin site on your left. Once a park residence, the cabin burned down several years ago. Beyond the cabin site, the trail climbs steeply for a short distance. As you climb, keep a sharp eye out for gray-brown chunks of sandy limestone in the soil. These chunks represent concretions encased in the Knoxville mudstone. Continue up the Donner Canyon 3/4 of a mile to the junction with the Meridian Ridge Trail. In springtime, look for the California State Flower, the Poppy, and the California State Bird, the Quail. Pause at the trail junction and examine California's State Rock, Serpentinite. Serpentinite is a metamorphic rock, created by the hydrothermal alteration by seawater of peridotite, the rock which comprises the mantle of the earth. The mantle is the layer of the earth's interior that lies between the relatively thin crust and the earth's core. Serpentinite is an ultramafic rock, rich in the elements iron and magnesium. Serpentinite also contains concentrations of nickel and chromium. This unusual mineralogy results in a distinctive plant community dominated by scrub oak, manzanita, and digger pine. Although only 1% of California is underlain by soil derived from serpentinite, fully 10% of California's endemic plant species grow in a serpentinite substrate. Turn right (west) at the junction of the Donner Canyon Road and Meridian Ridge Road, proceed uphill 1/10 of a mile on the Meridian Ridge Road and turn left at the intersection with the single-track Middle Trail. Finding the route to the falls was once a formidable task, but strategic intersections have been well marked through the determined efforts of Harvey Brossler, Paul Bennett, and other volunteers as part of an ongoing MDIA sponsored trail signage project. New trail posts have been erected throughout the park and signs are being affixed to the posts. Ranger Jay Sherman and former Ranger Burt Bogardas have also been instrumental in the project. The Middle Trail winds up the serpentinite hillside with serpentine twists and turns for 1/2 mile, to the junction with the Falls Trail. At the intersection, take the Falls Trail, which branches to the left. After another 1/4 mile climb, the trail dips to cross a creek. During the cold winter months, this creek crossing provides a truly remarkable spectacle. Here, thousands of ladybird beetles cover every rock, tree and shrub. "Ladybugs" spend the winter in semi-hibernation on Mount Diablo. When the weather warms, the ladybugs mate and fly off on prevailing easterly winds to coastal valleys where they will lay eggs to produce the next generation of beetles. As you continue up the Falls Trail, notice that the mottled serpentinite is replaced by a dark colored rock. This is basalt, an igneous rock erupted from volcanic vents on the ocean floor at tectonic plate spreading centers. These are the oldest rocks on the mountain. Radiometric and paleomagnetic studies indicate that the basalt is 190 million years old and formed thousands of miles out in the Pacific. These rocks were rafted here from their remote origin at spreading oceanic ridges by movements of the Earth's plates. The basalt is part of the Franciscan assemblage of rocks. The basalt on Mount Diablo is sometimes referred to as pillow lava. Molten rock that erupts underwater cools quickly on the outside while the inside of the flow keeps moving, pushing the mass into a tube or pillow shape. These pillow structures are especially conspicuous on the cliffs surrounding the falls. These rocks are also called greenstone because the erupting lava reacts with seawater to form new minerals, such as chlorite, which give the basalt a greenish cast. Finally, you will reach the Falls about 1/2 mile beyond "ladybug cove". Notice that the water flows over and through the basalt. Freshly formed basalt is generally not a good aquifer, but the rocks on Mount Diablo have been highly fractured over the millennia and so are able to store and transmit water to produce the seasonal waterfalls. Continue north along the Falls Trail. The fantastically contorted red rock is Franciscan chert. Chert is a biogenic sedimentary rock, composed of the recrystallized skeletons of single celled creatures called radiolarians. Radiolarians look like "amoebas in glass houses". These planktonic organisms live in the warm surface waters of tropical oceans and build their skeletons ("tests") out of silica. After radiolarians die, their tests slowly settle to the frigid bottom waters of the ocean floor to form a siliceous ooze. The ooze is buried, compressed, and over time, "lithifies" to form solid chert. Notice that the chert is in discrete layers, with bands of shale (composed of volcanic ash and fine silt blown from land) spaced in between ribbons of chert. The bedding develops when the soft ooze hardens to rock. In a process called diagenesis, the molecules of silica segregate themselves from the shale to form separate chert-shale couplets. Examine the intricate chevron folds. These folds develop during plate subduction, long after the ooze has hardened into solid rock. This is an example of "uniform flow" or "ductile deformation", in which solid rock deep underground is shaped under conditions of high confining pressure, high temperature, but low directed stress. The trail continues to climb briefly beyond the falls, then descends to meet Cardinet Oaks Road in 1/2 mile. As you descend, notice that the vegetation growing on the chert soil is rather sparse. In contrast to the Knoxville formation soil, soil derived from chert is both porous and permeable. This gives the soil a poor water holding capacity and serves as a limiting factor on the plant life. Walk down Cardinet Oaks Road and cross Donner Creek in .4 of a mile. As you cross the creek, see if you can identify the Franciscan cobbles and boulders that line the creek bed. Continue .1 miles to the junction of Donner Canyon Road, turn right, and return to the trail head. Thanks to Karen Synowiec and Roi Peers for their many helpful suggestions regarding the content and presentation of this article. Karen Synowiec is a professional geologist and MDIA hike leader. Doris Sloan, MDIA advisor, is Professor Emeritus of Environmental Studies at U.C. Berkeley. She teaches a California Geology class for the general public each spring through U.C. Extension. Along Falls Trail | Clayton Worsdell BACK TO LIST

Mount Diablo Buckwheat by Robert Sanders, UC Berkeley Press Release 2005 A Dainty Pink Mount Diablo Buckwheat Rediscovered January 1, 2005 Scott Hein BERKELEY – A petite pink flower that hasn't been seen in 70 years has been rediscovered on the flanks of Mount Diablo in Contra Costa County by a University of California, Berkeley, graduate student. The Mount Diablo buckwheat, Eriogonum truncatum , "has been a Holy Grail in the East Bay for several decades," according to UC Berkeley botanist Barbara Ertter, who confirmed the identification in the field on Friday. Last reported in 1936, the flower was presumed extinct, she said, because its habitat has been overrun by introduced grasses. It is one of only three plants, all of them rare, that are endemic to Mount Diablo. Michael Park had the missing buckwheat on his mind when he hiked out to a remote corner of Mount Diablo State Park on May 10, to a section that had been acquired and donated to the park by the organization Save Mount Diablo. Following a different routine from his normal survey, he stumbled across the plants - about 20 in all - in full bloom, looking like pink baby's breath. Less than eight inches tall, the annuals are inconspicuous, and were growing in a balding area between full chaparral and non-native grassland. Park's discovery thrilled native plant enthusiasts and conservationists like Seth Adams, director of land programs for Save Mount Diablo, a non-profit group dedicated to preserving Mount Diablo's peaks and foothills through land acquisition and other preservation strategies. "This is so monumental from our point of view," Adams said. The discovery site, a full day's hike from public trailheads in the park, is being kept secret for now so that admirers won't flock to the area and inadvertently destroy the rediscovered plant. "If it had really been lost, it would have been gone forever, and a unique part of our heritage vanished permanently," said UC Berkeley alumnus Peter Raven, director of the Missouri Botanical Garden and an internationally renowned botanist and conservationist. "Now we have the chance to understand it, to enjoy it and to know that we haven't done it in!" Ertter, the curator of western North American flora at UC Berkeley's Jepson Herbarium and co-author of the 2002 revision of Mary Bowerman's The Flowering Plants and Ferns of Mount Diablo, California, noted that one priority should be to gather seeds and start cultivating the buckwheat at the UC Botanical Garden. Cultivated specimens conserved by the garden, which is part of the Center for Plant Conservation network, will provide a reserve of seeds in case the species declines further. "At some point, if we have the mature seeds and can get them started in cultivation so there is a backup, then we can relax a little more," Ertter said. "At this point, it is really tenuous. Here, it's still hanging on by its fingernails, and the publicity alone could be enough to wipe it out again." "The worst threat to this plant is being loved to death," added Adams. Park, 35, began surveying the flora of Mount Diablo three years ago as part of Ertter's ongoing surveillance of the area's plants. Funded by the Jepson Herbarium's Heckard Fund, Park took on the task of surveying the plants on land newly acquired by Mount Diablo State Park. Much of this land was grazing land, but Park was pleased to discover that the many introduced weeds have not pushed out the native plants. "Fully 70 percent of the plants catalogued in the survey are native, and 70 percent of the 20 or so plants newly discovered or properly documented to occur in the Mount Diablo area during the course of my study are native," he said. Park included many of his findings in his senior thesis, which he completed last spring under the supervision of Bruce Baldwin, UC Berkeley professor of integrative biology and curator of the Jepson Herbarium. Now finishing his first year as a graduate student in the Department of Integrative Biology, Park found the buckwheat while completing his survey during a prime time of the year, when plants are flowering profusely after one of the latest and rainiest winters in decades. After he discovered the small population, Park "vacillated back and forth between excitement and denial." Finally accepting the fact that he had been in the right place at the right time, he divulged his secret to Ertter and alerted the park service. Two days later, he hiked with two fellow graduate students to take photos, which convinced Ertter he had indeed found the elusive buckwheat. First reported in 1862, there are only seven historical records of the plant, the last in 1936, when Bowerman, one of the first women to receive a Ph.D. in botany from UC Berkeley, collected a sample from Mount Diablo. She published her book of the flora of the mountain in 1944, as the summation of her dissertation work done under the guidance of Willis Linn Jepson, whose subsequent endowment established the Jepson Herbarium. Bowerman later went on to become one of the founders of Save Mount Diablo. The buckwheat is important, Ertter said, because it is the only presumed extinct plant restricted to the East Bay and one of only three plants endemic to the mountain, that is, found there and nowhere else. It has been found as far afield as Antioch and Solano counties, though not in the past 69 years. Park suspects that the unseasonably late rains may have produced the flowering, since many native plants produce seeds that remain dormant in the soil for decades until the right moisture conditions make them germinate. Brent Mishler, UC Berkeley professor of integrative biology and director of the Jepson and University Herbaria, noted that this is typical of plants in Mediterranean-type climates like California. "Mike is great. He's part of the long tradition of UC Berkeley's field botanists, from Jepson and Bowerman on down to Ertter, who have conducted the detailed studies of the flora of California that let us recognize a find like this," Mishler said. "It really demonstrates the importance of continuing floristic and systematic studies across the decades and centuries, the key role of herbaria and the need to maintain strong educational programs in these areas." As park officials discuss conservation plans for the rare plant, Park will continue to trek out to the buckwheat flowering grounds to learn how long it flowers and more about its life history. The hoopla over the find has interfered with his field studies at a critical time of year, but he says he's trying to enjoy it. "It was very exciting, and I've spent a few weeks being stunned over this thing," he said. "But I'll be glad when it's over." Mount Diablo buckwheat, with its characteristic branched flowers, grows along the edges of chaparral, in areas that have been partly cleared of grass by rabbits. BACK TO LIST