Copyright © 2023 by Dana York and James M. André.

All rights reserved.

Photo credits appear on here.

Endpaper maps by Vincent James

Map on here by Jeffrey Kane

Species nomenclature follows current taxonomy as presented on the Jepson Herbarium eFlora website (ucjeps.berkeley.edu/eflora/). Common names, often missing from the eFlora, are mainly drawn from the CalFlora website (calflora.org).

The information in this book is true and complete to the best of our knowledge. The authors and publisher disclaim any liability in connection with the use of this information. In particular, eating wild plants or using them medicinally is inherently risky. Plants can be easily mistaken and individuals vary in their physiological reactions to plants that are touched or consumed. This book is primarily a guide to identification and is explicitly NOT a foraging guide.

Published in association with the Pacific Crest Trail Association in 2023 by Timber Press, Inc., a subsidiary of Workman Publishing Co., a subsidiary of Hachette Book Group, Inc.

1290 Avenue of the Americas

New York, NY 10104

timberpress.com

The publisher is not responsible for websites (or their content) that are not owned by the publisher. The Hachette Speakers Bureau provides a wide range of authors for speaking events. To find out more, go to hachettespeakersbureau.com or email HachetteSpeakers@hbgusa.com.

The Hachette Speakers Bureau provides a wide range of authors for speaking events. To find out more, go to hachettespeakersbureau.com or email HachetteSpeakers@hbgusa.com.

Cover design by Johnny Bertram

Series design by Vincent James

eISBN: 9781643263199

Catalog records for this book are available from the Library of Congress and the British Library.

Cover: PCT through brittlebush; San Bernardino Mountains, near Cabazon Right: Joshua trees in the Tehachapi foothills

Back cover: Stephen Ingram (fifth); Steve Mason (bottom)

PREFACE

What better way to experience California’s unique plant diversity than to hike the state from end to end along the Pacific Crest Trail (PCT)? We have, and we hope you will too—with the help of this book, which covers the first 11 of California’s 24 PCT sections, heading from south to north and ending at Tuolumne Meadows (see front endpaper map). We have hiked, extensively explored, and researched plant collections from every California ecoregion (see back endpaper map), covering all 1692 miles of the PCT, from Mexico to Oregon.

According to the 2022 Consortium of California Herbaria (ucjeps.berkeley.edu/consortium), the earliest scientific plant collection on the California PCT was of Lemmon’s draba (Draba lemmonii), collected by Mark Kerr on 16 September 1941 near upper Woods Creek in Fresno County; John Muir Trail is specifically noted on the specimen label. Likely collections were made even earlier along the trail, but either the collector left the trail name off the specimen label or the trail was not yet formally named. In total, over 5000 vascular plant collections have been made from or near the trail in California. Using those collections as a baseline, we undertook three years of extensive fieldwork, beginning in 2019, to develop this guidebook.

The PCT is a very popular trail for hikers around the world, gaining prominence with Cheryl Strayed’s 2012 book and subsequent 2014 movie, starring Reese Witherspoon, Wild. But despite all its fame and use, we found surprisingly little information about the trail’s vegetation; and as we explored the trail, we were amazed by how many previously unknown populations of rare plants we found, often in plain sight. Having a way to identify plants along the California portion of the trail was lacking—until now.

This guide to Pacific Crest Trail Sections 1–11 covers more than a third of the 3000-plus native plants that occur along the California PCT. Plants were included if they have local significance (rare or endemic to a region), have showy flowers or fruits, are common along the trail, and/or would be of interest to hikers. Some rare plants and grasses and grass-like species were not included because they’re either hard to find or hard to identify, and (especially for rare plants) impacts from hikers could negatively impact them.

This guidebook is your treasure map to discovery. Have fun, be safe, and take time to smell the flowers!

Introduction

At over 2650 miles, the Pacific Crest National Scenic Trail, as it is officially known, traverses some of the most outstanding natural landscapes in the western United States, spanning three states and crossing numerous national parks and monuments, national forests, wilderness areas, state and county parks, and tribal lands. The trail climbs as high as 13,153 ft. elevation (at Forester Pass) and drops as low as 180 ft. (at the Bridge of the Gods on the Columbia River). Although it may be tempting to have help negotiating the trail’s rugged terrain, the PCT is intended for hiking and equestrian travel only. Motor vehicles and bicycles are prohibited.

The concept of a crest trail started over 100 years ago when the US Forest Service designated the Oregon Skyline Trail, from Crater Lake to Mt. Hood; the trail was later extended to traverse the entire state. An effort to create a trail traversing Washington began in 1928 with the designation of the Cascade Crest Trail. The US Forest Service eventually designed PCT markers and in 1937 started marking the trail from Canada to the California border.

The idea for California’s portion of the PCT began with Clinton Clarke, a prosperous oilman and avid scout leader. In 1932, he founded the Pacific Crest Trail System Conference, which included Ansel Adams as a member. He also made a proposal to the US Forest Service and National Park Service to form a continuous wilderness trail across the US from Canada to Mexico, eventually recommending linking the existing trails in Oregon and Washington with California’s Tahoe–Yosemite and John Muir trails.

In 1968, the PCT was named a national scenic trail, along with the Appalachian Trail. Over the following 20 years, land management agencies, the Pacific Crest Trail Association, and other groups and volunteers completed nearly 1000 miles of trail; the entire PCT was finished in 1993.

Today, the overall management of the PCT is the responsibility of the US Forest Service. Trail maintenance and permits for hikers going less than 500 miles are generally at the discretion of the agency/organization that manages the land being traversed. Thru-hikers, or anyone going more than 500 miles, are required to obtain a long-distance permit. Check the PCT Associations permit website for more information (pcta.org/discover-the-trail/permits). Although the trail has been complete for nearly 30 years, there are still over 200 miles of private land traversed and places where you are routed on roads, highway shoulders, and vehicle bridges.

The Washington portion of the PCT is around 506 miles long, with an additional 7 miles to hike from the Canadian border to Highway 3 in British Columbia’s Manning Provincial Park. Washington’s southern end begins at the Bridge of the Gods on the Columbia River. The main ecoregions (geographical areas with ecological similarity) traversed are the Cascades and North Cascades. Because ecoregions are based on relationships of climate, precipitation, geology, soils, hydrology, and wildlife, the plants are generally similar within them. The North Cascades ecoregion (275 trail miles) is the most rugged and pristine along the PCT. Unlike the volcanic Cascades ecoregion to the south, its geology is mostly metamorphic and sedimentary rocks. Much of the area was under glaciers until 10,000 years ago. Elevations above 4000 ft., which happens a majority of the time along this section of the PCT, are associated with subalpine and alpine vegetation. Because of the harsh, long winters, upper elevations are less species-rich than Washington’s coniferous forests below the subalpine zone.

The Cascades ecoregion (850 trail miles), spanning from Washington to California, is discontinuous along the PCT. From northern California into southern Oregon, the Cascades ecoregion is interrupted by the Klamath Mountains. The Cascades ecoregion is home to active and dormant volcanoes and has a predominantly volcanic geology. The vegetation of California’s portion of the Cascades and the Klamath Mountains is strongly associated with the species in the Cascades of Oregon and Washington. Mainly due to its relatively young surficial geology, the Cascades’ plant biodiversity is lower than California’s Klamath Mountains and Sierra Nevada.

The Oregon portion of the PCT (456 trail miles) falls mostly in the Cascades ecoregion. Volcanoes (both active and dormant) along or near the trail include (south to north) Mt. McLoughlin, Mt. Mazama (Crater Lake), the Three Sisters, Mt. Washington, Three Fingered Jack, Mt. Jefferson, and Mt. Hood. Moist, temperate conditions support extensive Douglas-fir (Pseudotsuga menziesii) forests with a mix of many other conifers, especially as you head north or gain elevation.

California (at 1691.7 trail miles, to be precise) accounts for nearly 64% of the PCT’s length. California’s high biodiversity is well known, especially when it comes to vegetation. Over 6600 native plants occur in the state. Its plant diversity is a result of surficial geology, physiography, climate (mostly temperature and precipitation), biotic influences (critters, other plants, and humans), and fire. California’s ecoregions traversed by the PCT (south to north) are Southern California/Northern Baja Coast (30 trail miles), Southern California Mountains (445 discontinuous trail miles), Sonoran Basin and Range (35 discontinuous trail miles), Mojave Basin and Range (33 discontinuous trail miles), Sierra Nevada (756 trail miles), Cascades (153 trail miles), and Klamath Mountains (242 trail miles). Almost half the PCT miles in California are in the Sierra Nevada ecoregion. Although the Sierra Nevada has more plants than any other California ecoregion, the PCT stays mainly in the upper elevations, missing much of that diversity. With that said, the flora of the Sierra Nevada is still spectacular and well documented in such places as Yosemite, Sequoia, and Kings Canyon National Parks.

Using This Guide

This guide was developed to help hikers or equestrians identify native plants along the southern half of the California portion of the Pacific Crest Trail (CA PCT). We aimed to include as many plants as possible, particularly those that are easily visible from the trail itself. Our general intent was that special tools or equipment would not be needed for identification. With that said, a phone camera can make identification much easier. Photos can be reviewed at your leisure and magnified if necessary. At times a hand lens would be beneficial, especially if fruits, nutlets, or seeds are helpful for identification.

Please practice good conservation techniques by staying on the trail and not picking flowers or collecting plants. Although we point out various cultural, medicinal, or historical uses for some species that you may be interested in trying yourself, always obtain proper permission from the land manager or owner before collecting any plants or plant parts. Also, do not consume any plant part unless you’re completely sure of a plant’s identity. Color is never a good sole indicator of edibility; red fruits are notorious for being either tasty or poisonous, for example. If in doubt leave them be—it’s not worth taking a chance along the trail, far away from medical facilities. The most poisonous plants have notes to that effect in the descriptions.

PCT Sections. We have divided the CA PCT into 24 sections (again, see front endpaper map), numbered and listed in entries from south to north; these divisions were based on likely access points and defined ecoregions as natural borders to those sections, as much as practicable. This volume covers Sections 1–11. We tried to select sections that have vehicle access (or close to it) at each end to accommodate section users. Section locations for plants covered by this book are from personal observations, historic records, and professional judgment as to the likelihood it would occur along the PCT within a particular section. We fully expect that some plants will be found by our readers in sections where previously unknown and not indicated.

Organization. Plants are presented in the following main categories: Conifers, Trees and Shrubs, Wildflowers, and Ferns, Horsetails, and Grasses. Further groupings based on characters such as leaf arrangement, color, etc., are alphabetically arranged, first by the family scientific name then the full species name. Conifers groupings are based on leaf type and number of needles per cluster. Trees and Shrubs groupings are based on leaf type and arrangement. Wildflowers (Flowering Herbs) are grouped by color. They are further grouped by type of flower or number of petals/sepals. Flowers with 5 petals or petal-like sepals are further divided by having symmetric/irregular flowers with free or fused (into an obvious tube) petals. Ferns, Horsetails, and Grasses are split into two sections (ferns and horsetails; grasses, sedges, and rushes).

Scientific Name. Species nomenclature follows current taxonomy as presented on the Jepson Herbarium eFlora website (ucjeps.berkeley.edu/eflora/). Variety and subspecies are included for plants where we felt it necessary to differentiate at a level below species. We often include the origin and/or etymology of scientific names. For more information, Wikipedia maintains an ongoing list at “plant genera named for people,” with links to publications where those names first appeared.

Common Name. Many sources were used for common names, with the main source being the CalFlora website (calflora.org). If more than one common name is often associated with a plant, we sometimes include alternative (aka = “also known as”) common names.

Abundance. You can use abundance information to help with plant identification. For example, if you keep seeing a species along the trail that you initially identified as a rare plant, then you probably misidentified it. Common plants are those found in great numbers along many miles of the PCT, in various habitats, and generally in many PCT sections. Locally common plants can have a large range with gaps of few to no plants in between. They’re not common along long portions of the PCT, but where they do occur, they tend to have large populations. Occasional plants are those encountered infrequently along the PCT. They could also be considered as uncommon. Rare plants are those with 1 to few populations on or near the CA PCT; many are restricted to one PCT section. For more details, see the California Native Plant Society (CNPS) Rare Plant Inventory at rareplants.cnps.org.

Height. Given in inches or feet, and represents typical heights of mature plants under normal conditions. If the height is off for a plant that you are looking at, try to find other individuals to see if there’s a range that makes more sense.

Flowering. The range indicated is the most likely time the plant blooms. With that said, atypical climatic conditions or other factors can result in plants blooming outside their normal time of year.

Flower Color. Flower color can vary, so you may have to check other colors for the plant you’re trying to identify. Detecting the difference between colors can be challenging, or flowers can change color as they mature. We recommend that if you don’t find your plant under a certain color, such as orange, you should try something similar like red. Using color and basic flower characters to identify plants is not perfect, but it is a system that doesn’t require learning tons of jargon. With a little practice, you will be efficiently figuring out flowering plants along the trail.

Habitat–Community. Where a plant grows is just as important as your address or phone number. A plant’s habitat is its natural home. It includes the living and nonliving conditions of a plant’s surrounding environment. The next chapter gives a detailed discussion of the habitats and communities used in this guidebook.

Elevation. The CA PCT mostly stays several thousand feet above sea level throughout the state. Since most plants have a clear upper elevation limit (due to things like snow, ice, etc.), you will notice that most entries don’t indicate a lower limit. The elevation given for a plant represents the most likely place to find it growing, but outlier populations at extreme low or high elevations are always possible.

Ecoregions. The ecoregions used in this guidebook are designated by the US Environmental Protection Agency. Their California map is too detailed and large to reproduce well in a book but can be accessed and downloaded at epa.gov/eco-research/level-iii-and-iv-ecoregions-state. Again, a simplified ecoregions map appears inside the back cover of this book.

Descriptions. Each begins with the plant type (such as tree, shrub, annual, or perennial) and generally stem and branch characters. Next, character and size information is presented for the leaves, flowers, and fruits. Entries often include explanations of a plant’s name or information about its uses.

Photographs. We took almost all the photos; any exceptions are listed in the photo credits. Most wildflowers have only a single photograph, and we acknowledge these may or may not show all important characteristics needed to identify the plant, especially if it’s not in bloom. Knowing that having a single photograph can make identification difficult, we recommend you look at all the information given for a plant in order to make a determination.

CALIFORNIA PCT FIRE ECOLOGY

— By Jeffrey M. Kane

Given recent and ongoing patterns of increased wildfire activity in California, it is likely that most PCT hikers will be impacted by fire in some way. Since 2000, over 350 fires have occurred along the PCT. Smoke from nearby wildfires may pose serious health risks. Hikers may need to evacuate areas due to wildfires. Sections of the trail will be closed because wildfire is actively burning or because recent fires have damaged the trail or pose other risks. These circumstances will inevitably pose challenges to planning and may affect the experience, but fires also provide opportunities to learn about its ecological role and the history of past practices that have led to these concerning wildfire trends.

The following table presents wildfire information for ecoregions that occur along the CA PCT. Fire information refers to large fires (≥500 acres) that occurred between 2000 and 2020. Burned area includes areas that have reburned during this time period.

Ecoregion

No. of Fires

Burned Area (acres)

Burned Area (%)

Cascades

15

94,301

2.7

Klamath Mountains

41

455,045

5.6

Mojave Basin and Range

28

70,139

0.4

Sierra Nevada

21

949,167

7.4

Sonoran Basin and Range

32

44,478

0.6

Southern California/Northern Baja Coast

208

951,680

24.3

For most ecosystems along the PCT, fire is an ecological and cultural process that is integral to numerous plant and animal species. A hike along the trail serves as tour that highlights the diverse roles of fire within and among many ecosystems in California. However, the ability of a hiker to observe the influence of fire on the landscape requires understanding the fundamental concepts of fire science and ecology.

Fire is a chemical reaction that, in the presence of sufficient heat and oxygen, combusts live and dead vegetation, commonly referred to as fuel. Fire behavior, or the pattern of movement and intensity of fire across a given area over time, is influenced by the interaction of weather, topography, and fuels. Depending on the fuels present and the patterns of fire behavior, there are generally three types of fire that can occur alone or in combination: surface fires, crown fires, and ground fires. Fires that burn through litter, grasses, or small woody fuels are surface fires and typically burn at relatively low intensities (amount of energy released during a fire) and low to moderate rates of spread (speed of the fire). Crown fires carry through the canopies of plants (shrubs and trees) and are typically much more intense and rapidly moving than surface fire. Ground fires predominantly burn by smoldering in the organic soil layers of duff or peat.

Fires can ignite by lightning, typically by striking a tree or ground that combusts by smoldering, which ignites the dead and dry litter or grasses that allows the fire to spread. Generally, lightning strike density in California increases from west to east as well as from lower to higher elevations, with the highest lightning density observed in the high Sierra. Fires are also intentionally ignited by humans. Across California, numerous Indigenous peoples utilized fire to manage the landscape for a diverse array of benefits for most of the previous 11,000 years, a practice that was villainized and violently disrupted in the 19th century and afterward but that persists in many regions today. In many regions, most modern ignitions are the result of unintentional human ignitions that result from a number of activities.

In the early 20th century, many foresters perceived wildfire as damaging to forests in the western US due to the loss of merchantable timber. These perceptions were largely generated because nascent federal foresters were trained in regions and countries where forests did not regularly experience fire—a perspective that was strongly reaffirmed following the 1910 fires, referred to as the “Big Blowup,” which burned over 3 million acres (an area approximately the size of Connecticut) in the northern Rocky Mountains. Soon after, federal forest policy decisions focused on a zero-tolerance philosophy of fire, in which all fires are to be prevented and extinguished—perhaps best exemplified by the 10 a.m. policy from 1935 that mandated all wildfires were to be suppressed by 10 a.m. the morning of or following wildfire ignition.

The perception that fire was a damaging agent to be eliminated was not uniformly shared. Indigenous peoples in many regions resisted these policies by continuing their burning practices, which had helped sustain their communities for many millennia but were now deemed as illegal. Other groups, primarily ranchers and private foresters who likely learned about burning through interactions with Indigenous peoples, actively advocated for the beneficial role of “light burning” fires. Unfortunately, these voices ultimately lost out to fire suppression practices that aimed to “protect” forests from fire.

It is also important to point out that direct fire suppression was not the sole means of change contributing to the fire-related issues of today. The removal of fire from the landscape was indirectly facilitated decades earlier through the intentional genocide and removal of Indigenous peoples from their ancestral lands. Intensive grazing practices of the past also contributed to the removal of fire. Many grasslands were effectively denuded by sheep and cattle that would have limited fire spread throughout much of California, conditions that would have also favored conifer and other tree establishment. Furthermore, the fire suppression policies coincided with intensive and extensive logging that cut most of the old legacy forests that were once much more prevalent in California. Following logging, areas were subsequently planted or allowed to naturally regenerate, eventually becoming the dense, young forests that make up a large portion of the forest conditions today. The consequence of these past actions and policies all contributed to the circumstances of fire we are now dealing with. Denser, more contiguous young forests that established across many landscapes due to fire exclusion can yield more damaging and destructive fires when they burn.

Beginning around 1960, western US researchers began to realize the limitations of excluding fire from ecosystems. These perspectives highlighted the need to reintroduce fire to many of California’s landscapes. Soon after, many managers began to use prescribed or controlled burning to manage historically fire-prone ecosystems. In the 1970s, the National Park Service and Forest Service incorporated a policy of allowing lightning-ignited wildfires in wilderness areas in the Sierra Nevada of California and other regions in the western US to burn under desired conditions to reduce fuels, improve forest conditions, and promote other resource benefits.

Despite the increasingly aggressive (and more costly) efforts to suppress fires in California throughout much of the 20th century, the recognition of fire’s ecological importance, and the increased use of prescribed and managed wildfires for resource benefit, the frequency of large wildfires increased in the mid-1900s. This increase in fire activity over the past few decades is largely attributable to increasing temperatures and greater aridity, a direct impact of climate change—a pattern that was most pronounced in 2020 and 2021, when nearly 7 million acres burned in California. Changes in fire severity (amount of living vegetation killed by fire) across California have been more varied. In the Sierra Nevada, there has been demonstrated increases in fire severity over the past four decades. However, in the Klamath Mountains, increased fire activity has not coincided with increases in fire severity, but the size of high severity patches has increased. While the fire activity in California has increased, it remains below pre-EuroAmerican settlement levels (one estimate is that an average 4.5 million acres burned annually in California), and a substantial fire deficit persists.

Prior to fire exclusion, California ecosystems burned in relatively consistent patterns of seasonality, intensity, severity, size, patchiness, and frequency, or what is commonly referred to as a fire regime. Similar to the way that climate represents the culminating patterns of day-to-day weather fluctuations in an area, fire regimes reflect the cumulative pattern of individual fires over time for a given area. Fire regimes vary over time and space within and among plant community types but still can be classified broadly into three broad categories based on frequency (number of fires that occur over time) and severity (proportion of living biomass killed by fire): 1) low severity (high frequency), 2) mixed severity (moderate frequency), and 3) high severity. All three fire regime types are found along the PCT in California. Fire severity is often inversely related to fire frequency so that high frequency fire regimes typically have low severity fires and low frequency fire regimes have high severity fires. Yet, there are some ecosystems where low intensity fire can result in high severity.

California contains a diverse array of plant communities, each of which can be characterized by one of the three general fire regime types just described. In the desert regions of southern California, plants communities such as creosote bush scrubs, mixed woody scrubs, and Joshua tree woodlands are typically fuel-limited, meaning that low levels of precipitation result in relatively low productivity that limits the spread of fire. These conditions result in very low frequency fires (>500 years) with burns resulting in predominantly high severity. Other plant communities in arid regions, containing species such as pinyon or juniper, are also fuel-limited, burning at high severity every 50–100 years. Foothill and montane chaparrals will also burn at high severity, with fires occurring historically, on average, every 30–60 years. High-elevation plant communities, such as subalpine coniferous forests and alpine, also are characterized as low frequency–high severity fire regimes that historically burned every century or so. However, fire in these communities is limited due to higher fuel moisture content because of the higher precipitation levels and cooler temperatures in these environs. Plant adaptations to fire in these fuel-limited plant communities tend to be uncommon. Most plant species persist through unburned refugia or by recolonizing areas from the unburned edges. The exception to this is chaparral plant communities that have a number of plant adaptations that facilitate fire or promote recovery following fire. Many chaparral shrub species have the ability to resprout following fire, while others prolifically regenerate from seed stored in the soil. The germination of these seeds are often stimulated by the presence of heat and smoke. The architecture of the shrubs and retention of dead branches also facilitate the spread of high severity fires, which provides growing space for seedlings. Many species also experience enhanced flowering following fire including many fire ephemerals or followers (short-lived plant species that establish in the first few post-fire years).

Lower-elevation plant communities, such as California prairies, oak woodlands, and lower montane conifer forests, often tend to have high frequency–low severity fire regimes. Fires in these ecosystems tend to result in low severity, burning every 15 years or less. Many of the tree species in these ecosystems tend to have relatively thick bark (e.g., ponderosa pine, California black oak) and self-pruning branches. The leaves and needles of these species are also highly flammable due to their creation of dry porous litter beds that promote rapidly moving low intensity fires that are helpful to limit fire damage to the bole and reduce potential competitors, among other benefits. Evidence of frequent fire in these forest types is determined based on fire scars at the base of trees. In the prolonged absence of fire, these ecosystems are most impacted because they typically result in substantial increases in shade-tolerant competitors; these lead to dense stand conditions with higher amounts of fuel and greater continuity, which can result in higher intensity fires that can kill otherwise fire-resistant trees.

Upper montane conifer forests tend to have low or mixed severity fire regimes. Fires in these forests historically burned every 10–40 years. Fire severity in these forest types is usually a mixture of low, moderate and high severity patches, with most burning at low and moderate severity. Many conifers in these forests have adaptations similar to those present in low severity fire regimes. However, some forests contain species that require higher severity fires such as knobcone pine. These species have serotinous cones that open with fire. The adult trees have thin bark and die after the fire, but the seeds from serotinous cones prolifically establish on the exposed mineral soil the year following fire. The upper montane zone also contains lodgepole pine forests. Fire’s role in these forests is interesting because although they are not technically serotinous (all cones open within a year), seedlings commonly establish after fire similar to serotinous species. This is likely because most fires occur in the late summer or early fall when the current cone crop contains mature seeds and is still closed. Thus, once fire comes through, the seeds stored in the cone can establish after the fire, though presumably at lower densities than truly serotinous species.

The role of fire in the many ecosystems present along the PCT is quite evident and in most cases ecologically and culturally beneficial. However, the unfortunate legacy of past management practices and the ongoing challenges related to climate change can result in undesired impacts from wildfires. Still, a hike along the PCT would not be representative without the clear evidence of fire on the landscape.

Plant Communities and Habitats

You may notice vegetation occurring in repeating patterns as you traverse California’s various landscapes on the PCT. For 100 years or more, ecologists have mapped and classified these patterns using methods that included species composition, structure, and/or environmental conditions. As practicable, the plant communities are presented here in order of increasing elevation.

PCT Sections: All Elevation: Below 10,500 ft.

Wetland-Riparian Communities

Found from desert arroyos to subalpine zones throughout California. Habitats include bogs, fens, lakeshores and lakebeds, marshes, wet meadows, ponds, riparian forests and scrubs, seasonally wet depressions, seeps, shallow lakes, springs, and streambanks. Meadows, streams, lakeshores, and other wet places above tree line are included in Alpine Communities.

Basically, when you go to fill your water bottle below the alpine zone, you’re in a wetland-riparian community. It also includes areas of near-surface water. These are important places not only for us, but for wildlife. Indigenous peoples have used fire over the past 10,000 years in California to keep meadows open and accessible for themselves and game species. While keeping tree species such as lodgepole pine (Pinus contorta subsp. murrayana) from encroaching, burning also removed old, decadent vegetation from meadows and riparian habitats, allowing for species such as rushes (Juncus spp.), grasses, and sedges (Carex spp.) to thrive with lots of new growth. With new, nutritious foliage to munch on, plus plenty of available drinking water, grazing animals such as elk and deer would gather and thrive in burned wetlands. Yosemite and other national parks have brought fire back to their shrinking meadows to open them up again or at least to slow the encroachment of woody vegetation. Using controlled burning, or allowing natural fires to burn through meadows and riparian habitats, is gaining popularity with land managers throughout California.

PCT Sections: 1–4 & 7 Elevation: Below 4500 ft.

Creosote Bush Scrubs

Structurally dominated by creosote bush (Larrea tridentata, pictured above), this ubiquitous desert scrub community is limited to the most arid low-elevation stretches of the CA PCT that bisect the Sonoran and Mojave Basin and Range ecoregions. Habitats include gravelly slopes and alluvial fans to sandy well-drained basins. It intergrades with Sonoran and Mojave Mixed Woody Scrubs and Joshua Tree Woodlands at higher elevations, and with Saltbush Scrubs where soils have higher salinity.

White bursage (Ambrosia dumosa) is often codominant with creosote bush, and the two species together represent the most common species in California’s Sonoran and Mojave deserts. Creosote bush clonal rings are known to live up to 11,000 years, and undisturbed ancient stands represent the oldest of California’s old growth vegetation! While a few widely spaced shrub species dominate this plant community, it’s worth noting that annual plants comprise 50–70% of its species composition. Urbanization, off-road vehicles, and the recent sprawl of solar and wind development threaten this plant community, especially along the PCT in Kern County.

PCT Sections: 1–4 Elevation: Below 4500 ft.

Sonoran Mixed Woody Scrubs

Found along the CA PCT on the desert flanks of the eastern Peninsular Ranges (San Felipe Valley region and lower Snow Creek drainage of the San Jacinto Mountains) and the southeastern San Bernardino Mountains. It is generally a transitional vegetation between the Creosote Bush Scrubs at lower elevations and the Pinyon-Juniper Woodlands and Montane Chaparrals above. Habitats include alluvial fans, rolling hills, and steep, rocky slopes with shallow soils. Plants are generally of Sonoran and southern Mojave Desert affiliation, with no clear dominant species. The various assemblages are highly diverse, containing a mix of both deciduous and evergreen woody shrubs and succulent species, including desert agave (Agave deserti var. deserti), California barrel cactus (Ferocactus cylindraceus), and Mojave yucca (Yucca schidigera). Species composition is influenced by summer precipitation; numerous shrubs and summer annuals are able to initiate growth and late-season flowering when activated by a warm-season precipitation event.

PCT Sections: 3–8 Elevation: Below 5000 ft.

Mojave Mixed Woody Scrubs

This diverse scrub community is common throughout the Mojave Desert at mid-elevations. Along the CA PCT, it is intercepted only along Mojave Desert–influenced stretches of the Transverse Ranges and southern Sierra Nevada, where it is a transitional vegetation between Creosote Bush and Saltbush Scrubs below and Pinyon-Juniper Woodlands above. It may also intermingle with Joshua Tree Woodlands and Black Bush Scrubs. Often occurs on moderate slopes or on dynamic alluvial fans; soils are shallow, well drained, and gravelly to somewhat rocky, usually derived from granitic materials. These complex scrubs may contain 15–20 codominant shrubs and as many as 45 shrub species per acre! White bursage (Ambrosia dumosa), black bush (Coleogyne ramosissima), narrowleaf goldenbush (Ericameria linearfolia, pictured above), creosote bush (Larrea tridentata), Joshua tree (Yucca brevifolia), and Mojave yucca (Y. schidigera) are often key constituents, but none are dominant.

PCT Sections: 1–7Elevation: Below 4000 ft.

Saltbush Scrubs

A low-diversity scrub type found intermittently in the valleys and drainages traversed by the CA PCT in the southern trail segments. Habitats include dry basins, sandy benches along watercourses, mudflats, and disturbed areas. Soils are fine-textured, poorly drained, and of high alkalinity or salinity. Because soils with high salt content are toxic to most species, total shrub cover is usually low, and few herbaceous plants occupy the open ground between shrubs. Saltbush Scrubs are typically dominated by one or more shrub species in the Chenopodiaceae, or by other salt-tolerant species. These “xero-halophytes” are well adapted to tolerating dry, saline soils; some absorb salts and store them in their tissues and in doing so may balance the pH of soils. Native species such as four-wing saltbush (Atriplex canescens, pictured above) and various goosefoots (Chenopodium) have been used in the rehabilitation of over-irrigated agricultural soils or soils contaminated by road salt or depleted by groundwater pumping.

PCT Sections: AllElevation: Below 10,000 ft.

Sagebrush Scrubs

Found in all the CA PCT ecoregions in dry washes, plains, valley bottoms, mountain slopes, streambanks, and ridges, generally in well-drained, sandy to loamy soils. Often occurs and is codominant with bitterbrush (Purshia tridentata). Sagebrush (Artemisia tridentata, pictured above) is the quintessential shrub of the Great Basin Desert. Fire plays an important role in maintaining healthy sagebrush stands, and fire intervals of 30–70 years are typical. Increased fire frequency or severity, however, may prove deleterious as sagebrush does not sprout after fire and is totally reliant on an established seedbank or adjacent plants to recolonize a burn. When fires are too frequent or severe, the seedbank is depleted, and the landscape generally becomes dominated by weeds. Disturbance, especially from cattle or vehicles, leads to an increase of invasive, nonnative plants.

PCT Sections: AllElevation: Below 12,000 ft.

Rabbitbrush Scrubs

Rabbitbrush Scrubs are more common in the intermountain states but appear along the CA PCT as well, most often in the southern Sierra Nevada. California stands are dominated by subspecies of rubber rabbitbrush (Ericameria nauseosa, pictured above), many of which have extensive ranges throughout the state. Casting a gray-green hue on the landscape, this community stands out from the more common stands of Sagebrush Scrubs, Pinyon-Juniper Woodlands, and forest associations. Habitat characteristics include well-drained soils in valleys, alluvial fans, and pediments at the base of slopes. Soils, usually of high clay content, may “self-till,” shrinking and swelling with the wet-dry precipitation cycles emblematic of California. Rabbitbrush Scrubs have a reputation for being a disturbance-follower, thriving on abandoned (tilled) agricultural property, overgrazed lands, burned areas, and along roadways.

PCT Sections: 1–2 & 8Elevation: Below 6000 ft.

Black Bush Scrubs

Of all the desert-affiliated plant communities along the CA PCT, perhaps none is more dominated by a single species than is Black Bush Scrub. On dry, well-drained slopes and ridges, black bush (Coleogyne ramosissima, pictured above) forms a monoculture of low, intricately branched, dark grayish green shrubs. While quite common in the Mojave Desert and western Sonoran Desert of California, the only known stands of Black Bush Scrubs along the PCT occur in the San Felipe Valley region of San Diego County and just north of Kelso Valley in Kern County, separated by about 520 trail miles! Black bush grows in shallow, often calcareous soils with a well-developed crusty caliche layer. Some mature stands may exceed 500 years in age. These ancient stands have not fared well with increased fire frequency in recent years. The shallow-rooted plants rarely survive a burn, and post-fire recovery, which may take decades, is limited to germination of seeds cached by rodents.

PCT Sections: 1–8 & 18–19 Elevation: Below 4000 ft.

California Prairies

Prairies along the CA PCT are associated with valleys and foothills mixed with oaks or shrubs, or open, treeless expanses. They also include native annual species such as California poppies (Eschscholzia californica), lupines (Lupinus), phacelias (Pacelia spp.) and popcorn flowers (Plagiobothrys spp.), all pictured above. With increasing elevation, prairies generally transition into woodlands or chaparrals. Unfortunately, because of intensive grazing, agriculture, and human development, California Prairies mostly consist of nonnative annual grasses and herbs such as wild oats (Avena spp.), bromes (Bromus spp.), star-thistles (Centaurea spp.), and filarees (Erodium spp.). Fire can have positive effects on this habitat by reducing nonnative species, especially grasses and their thatch buildup, allowing native plants to germinate. Fire was likely infrequent in California Prairies due to the low occurrence of lightning strikes, but grasslands close to habitation by Indigenous peoples were likely burned to attract wildlife with a proliferation of lush, new vegetation the following spring.

PCT Sections: 4–9Elevation: Below 7000 ft.

Joshua Tree Woodlands

Joshua tree (Yucca brevifolia, pictured above) has an extensive range throughout the Mojave Desert and is encountered along the Mojave Desert–influenced segments of the CA PCT. Though it rarely dominates a plant community, in denser stands this small tree becomes structurally significant. Joshua Tree Woodlands range along the PCT from sandy flats, such as those in the Antelope Valley, to elevations as high as 7000 ft. on the transmontane slopes of the San Bernardino Mountains and eastern Sierra Nevada and Tehachapi Mountains. They intergrade at lower elevations with Creosote Bush Scrubs and at higher elevations with Pinyon-Juniper Woodlands. Joshua Tree Woodlands, especially in Kern County, are subject to habitat degradation due to grazing, recreational activities, altered fire regimes, and more recently by the rapid sprawl of renewable energy development.

PCT Sections: 1–10Elevation: Below 8500 ft.

Pinyon-Juniper Woodlands

Pinyon-Juniper Woodlands take on many forms across the southwestern US but are especially symbolic of the vast Great Basin Desert. Along the CA PCT, several combinations occur; the most common involves singleleaf pinyon pine (Pinus monophylla, pictured above) and California juniper (Juniperus californica). This plant community occupies the mid-elevation transmontane slopes of the southern Sierra Nevada and Southern California Mountains ecoregions, where precipitation is 9–17 in. annually. In the Peninsular Ranges, Parry pinyon (P. quadrifolia) is added to this plant community. Pinyon pines and junipers have slow growth rates and are poorly adapted to fire. Over the past several decades, land management agencies have cleared Pinyon-Juniper Woodlands for the benefit of range and fire management programs. Environmental groups, tribal leaders, and other conservationists have argued that removing these trees is harmful to this storied plant community.

PCT Sections: 1–10 & 16–24 Elevation: Below 7000 ft.

Oak Woodlands

Oaks can be found on every section of the CA PCT, and in this community, oaks are the dominant tree. Oak Woodlands commonly intermix with Pinyon-Juniper Woodlands, Foothill Chaparrals, Lower Montane Coniferous Forests, and Montane Chaparrals. Fire is an important component in maintaining most Oak Woodlands. Frequent, low to moderately intense fires create openings for seedlings and sprouts. There’s evidence that Indigenous peoples maintained stands of oaks for acorn production by having frequent, low intensity fires. The most common oak here is canyon live oak (Quercus chrysolepsis, pictured above).

PCT Sections: 1–6 & 8 Elevation: Below 6000 ft.

Foothill Chaparrals

Foothill Chaparrals are the major vegetation type at lower elevations of the various mountain ranges. As you hike the CA PCT, Foothill Chaparrals tend to be the first shrub-dominated community you’ll encounter above California Prairies, and as you gain elevation, they transition into woodlands or Lower Montane Coniferous Forests. Although Foothill Chaparrals are dominated by shrubs, they can include small trees. Dominant species include chamise and red shank (Adenustema spp.). manzanitas (Arctostaphylos spp.), and ceanothuses (Ceanothus spp.). Fire intervals in this community may vary from 10 to 100+ years. Many of the dominant shrubs can sprout following fire, but frequent high intensity burns can eliminate chaparral altogether. Competition from nonnative plants, following disturbances such as fires or manual clearing, can also hinder the return of native chaparral species.

PCT Sections: AllElevation: Below 11,000 ft.

Montane Chaparrals

This mountain community is typified by dry, brushy areas between stands of trees. It may include some of the same species that occur in Foothill Chaparrals, as well as shrubs requiring the increase in precipitation associated with the montane zone. Dominant species include manzanitas (Arctostaphylos spp.), ceanothuses (Ceanothus spp.), and chinquapins (Crysolepsis spp.). As you continue to gain elevation above timberline, Montane Chaparrals and associated Subalpine Coniferous Forests transition into Alpine Communities. Fire interval range is 20–75+ years. Although many of the dominant shrubs can sprout following fire, frequent or high intensity fires can eliminate chaparral completely. After burning, rocky sites tend to stay shrub-dominated, while other, less harsh sites can eventually convert into coniferous forest as long as the fire-return interval is long enough for trees to become dominant.

PCT Sections: AllElevation: Below 8800 ft.

Lower Montane Coniferous Forests

Conifers are a quintessential part of the PCT experience as one hikes above the scrubs, woodlands, and chaparrals. At lower elevations, Lower Montane Coniferous Forests (aka mixed coniferous forests) transition into woodlands or shrub-dominated habitats. The upper limits of this community are not always clear as you transition into a preponderance of dominant trees associated with Upper Montane Coniferous Forests. Moister sites tend to favor white fir (Abies concolor), sugar pine (Pinus lambertiana), and Douglas-fir (Pseudotsuga menziesii). Fire is an important component of this community, especially when pines dominate. With livestock grazing and fire exclusion, pine stands can be replaced by more shade-tolerant trees like white fir and Douglas-fir. Climate change is linked to altered fire frequency and intensity, and more and more, forest fires result in complete stand replacements. In other words, forests along the trail may never return to tree-dominated communities. Loss of seed banks and viable sprouting material, generally drier conditions (climate change), and competition from nonnative plants are major factors working against coniferous forests returning along recently burned portions of the trail.

PCT Sections: 3–5 & 10–24Elevation: Below 11,200 ft.

Upper Montane Coniferous Forests

As you transition out of Lower Montane Coniferous Forests by gaining elevation or by moving onto cooler, moister slopes (often north-facing), red fir (Abies magnifica), lodgepole pine (Pinus contorta subsp. murrayana), and/or mountain hemlock (Tsuga mertensiana) become more dominant in the landscape. Lodgepole pines tend to occupy cold, moist habitats near meadows, lakes, and streams; red firs prefer slopes where winter snow accumulations are deep (to 20 ft.). For lodgepole pines, large stand fires tend to happen at long intervals, sometimes several hundred years between events. Lodgepole pines establish after burns with wind-dispersed seeds; surface fires tend to happen every 20–30 years. Red firs have a different relationship with fire; surface fires mostly occur at intervals of 10–65 years. Intense, large fires are very rare since fuels are often moist and compact, or just very sparse.

PCT Sections: 3–5 & 10–24Elevation: Above 8000 ft.

Subalpine Coniferous Forests

As you continue going up in elevation, this is the last plant community containing conifers. It is a boreal forest, bordering Alpine Communities and forming the timberline ecotone. Elfin, weather-battered, stunted trees that look like shrubs (aka krummholz) are common on exposed ridges within this community. Lightning strikes are also common, but fires are generally restricted to one or few trees. The shrub and herbaceous layers are mostly open and sparse, slowing the spread of fire. Foxtail pines (Pinus balfouriana) occur with the whitebark pines (Pinus albicaulis), which are the quintessential tree occupying this zone from the southern Sierra Nevada to the Klamath Mountains. Whitebark pine seeds are mostly scattered by Clark’s nutcrackers and squirrels. Summer climate is mild, with maximum temperatures normally not exceeding 65°F.

PCT Sections: 10–15 & 18Elevation: Above timberline (over 9500 ft.)

Alpine Communities

Besides the desert communities, plants in these communities, which include snowbank margins, talus and scree slopes, and meadows, face some of the harshest conditions along the PCT. Extreme wind, cold, lingering snow, and generally thin, rocky soils limit plant diversity mostly to low, tufted perennials (aka cushion plants). Plants can also seek protection from the elements by growing in protected rock crevices, between rocks, and at the base of boulders. Dominant species include Sierra columbine (Aquilegia pubescens), sedges (Carex spp.), and paintbrushes (Castilleja spp.). Lightning strikes are common, generally striking rock without causing any fires. Summer climate is very mild, with maximum temperatures normally not exceeding 60°F. The optimum growing season is limited to 4–7 weeks in summer, but hard frosts can happen year-round!