Historical Review of Plant Collecting in the San Gabriel Mountains
San Bernardino County Portion

Dick Swinney
Copyright February 19, 2010

A Chronological Review - Introduction - SB County

The following introduction to this review and the description of the study area, is precisely the same as the companion review, which presents the same plant species in a phylogenetic sequence.

San Gabriel Mountains Study Area:
The main east-west block of this mountain range has been selected for the presentation of the flora of the San Gabriel Mountains, exclusive of the Liebre Mountains which are included in most map publications. Discussion and explanation regarding the exclusion of the Liebre Mountain portion, will be entertained at a future date. The Liebre Mountain Block, projects to the north-west, between the Tehachapi Mountains to the immediate west and the Mojave Desert to the north and east. The Liebre Mountains are considered by most sources to be included in the San Gabriel Mountain Range. A large number of plant species found in the Liebre Mountains are not found in the main east-west block that lies to the immediate south. Many of these plants of course are found in the surrounding Mojave Desert areas to the north and east. A comparative study between the floral elements of the Liebre Mountains in contrast to the main east-west block of the San Gabriel, will not be attempted at this time. Such a study would be of great value to the understanding of the floras present in both areas. The lesser degree of the coastal influence in the Liebre Mountains, of course would be a major consideration for examining the sources of climatic differences.

Even though the Liebre’s are not located in San Bernardino County, they are discussed here because of the significance of their absence when considering both Los Angeles and San Bernardino Counties. The Historical Review of Plant Collecting in the San Gabriel Mountains - Los Angeles County Portion, was completed by the author in September of 2009. Both Phylogenetic and Chronological listings were prepared. I plan to combine both of these publications to present a complete list of plants using the the earliest dates from either county.

Choosing to delineate the north-eastern boundary of the San Gabriel Mountains by selecting the southern-most ridge line of Baldy Mesa, from Pinon Hills in the west to Cajon Summit in the east, is admittedly arbitrary. Defense of a more northerly development of boundary lines on Baldy Mesa, extending north into the town of Phelan and along the I-15 Freeway in the east, could be made I’m sure, with some convincing arguments. My major concern was finding a defensible boundary line in the far-eastern area, where the elevation is much more consistent, as it joins the floor of the southern Mojave Desert. I would imagine that careful consideration of the boundaries between the several plant communities in this area would become an integral part of a determination of a more northerly boundary line.

Description of boundaries:
Western Boundary: It follows along the LA/SB County Line, from Pinon Hills on the north (desert) side of the range, to the Upland area, at the San Antonio Dam on the southern (coastal or cismontane) side of the range.
Eastern Boundary: It follows along the Cajon Wash to the far southern portion of Glen Helen Regional Park, extending north along the Cajon Wash to Cajon Junction at Highway 138, where Cajon Wash turns west up Cajon Canyon. From Cajon Junction, the boundary roughly follows the I-15 Freeway. northward to the Summit of Cajon Pass at Baldy Mesa.
Northern Boundary: At the north-western boundary in the Pinon Hills area, the boundary follows the north base of the San Gabriel Mountain foothills, eastward to Baldy Mesa. Here, the boundary continues east along the crest of Baldy Mesa as it overlooks the town of Phelan to the north and the Cajon Canyon to the south. It terminates at the Cajon Summit.
Southern Boundary: At the south-west boundary along the county line, at San Antonio Dam in Upland, the boundary continues eastward at the base of the south-facing slopes of the San Gabriel’s through the cities of Upland, Rancho Cucamonga, Etiwanda and Fontana, to the mouth of Lytle Creek Canyon. The boundary continues to the east following the south-facing slope above Devore Road until it reaches Sycamore Flats, also called Muscupiabe. This low-refief foothill area dips to the south along the Cajon Wash. All but the southern portion is owned by the Glen Helen Regional Park. It continues south-eastward until reaching the Cajon Wash at the southern tip of this south-projecting foothill area at an elevation just under 2000 ft. (610 m.)

Study Description and the Consortium of California Herbaria:
The list of plant species included here have been compiled from the Consortium of California Herbaria data base of plants, as well as a partial survey of the plants from the Rancho Santa Ana Botanic Garden Herbarium, found in the San Bernardino County portion of the San Gabriel Mountains. The Consortium produces a plant database from fifteen contributing California Herbaria which is continually being updated. The database of course, does not include all plant specimens collected in the study area, but provides the most complete collection of plant records available at a single source and should include a majority of the plants found here. Only plants found in the Consortium and in the RSA Herbarium(described below), will be listed here unless otherwise noted. The Consortium was referenced from October of 2009 through February of 2010 for the majority of the entries found in this review. The data from each year was evaluated by examining the entries for the entire San Bernardino County. If the words San Gabriel Mountains are entered into the Consortium database, many marginal areas and even some areas within the study area would possibly be left out. This would depend on how the location was described on the plant voucher label. A careful examination of the location description is often necessary. Many entries had to be examined to determine whether the plants were collected in irrigated conditions. Such plants were not included. The most difficult area to determine in this last category included much of the area within the Glen Helen Regional Park. The extensive irrigation system for the park lawns, which run right to the edge of man-made lakes and natural seeps, makes these determinations difficult. Hopefully, descriptions of some of these difficult plants will be sufficient enough to allow you to make your own determination of the advisability of inclusion.

Rancho Santa Ana Botanic Garden Herbarium:
The Rancho Santa Ana Botanic Garden Herbarium Database provides the largest single collection for San Gabriel Mountain plants. Approximately 75 percent of RSA’S plant specimen data has been entered into its database. The percentage of the RSA database that has been uploaded onto the Consortium of California Herbaria Database is uncertain, but it is not complete. For this reason, I have begun a search of their database as well. The results shown in this paper include a search from 1824 to 1920, by examining the entries for the entire county of San Bernardino. I will continue the search of the database to the present time. I plan to create updates each year to include new entries.

All plant names have been annotated when necessary to conform with the latest scientific names as presented by the USDA Plant Database - 2009-2010, unless otherwise stated. The latest available reference for plant names of the San Gabriel Mountains is found in The Jepson Manual Higher Plants of California, edited by James C. Hickman, 1993. A new edition is currently being prepared. Many of the plant names in the 1993 edition, are no longer current. Plants recorded with no subspecific names are referred to as the nominate subspecies. Some of these in fact, may not have been determined to the subspecific level and may not be the nominate taxa. No attempt was made in this study to clarify the status of the nominate species.

Survey Focus:
The main focus of this study is to provide a comprehensive, although not a complete listing at this time, of plant species found within the study area, by presenting the first specimens collected for each species. The collectors name, collection location and date, will be provided for each specimen. The elevation at which they were collected will be included when available. Added information for the purpose of clarification by the author, is enclosed by parentheses. Within the parentheses, the words “added-2009 or 2010” have been placed at the end. Parentheses without the words “added-2009”, are simply data from the original voucher label.

The earliest date found for collected specimens for the San Bernardino County portion of the San Gabriel Mountains, was 1824, by Marcus Jones. The earliest record for the Los Angeles County portion was 1860, by William H. Brewer. There are 1444 plant taxa included in this publication. This representsl an inflated number, as many of the nominate subtaxa listed, most likely have not been determined to the sub specific level.

Place name discrepancies and location descriptions:

There are many references to Horsethief Canyon as being located in the San Gabriel Mountains. Horsethief Canyon is actually located in the San Bernardino Mountains within 3.1 miles east of Cajon Pass at Cajon Junction (Junction of Highway 138 & I-15 Freeway) If the specimen was collected in the San Gabriel Mountains, then the location is most likely Horse Canyon, which is within 6.2 miles west of Cajon Pass. The location names listed on the voucher data section will be listed as shown on the voucher.

Swarthout Valley references are often listed with the spelling of Swartout Valley. It is possible that some early maps displayed this spelling. The spelling displayed on the voucher labels has been retained for this publication.

The San Bernardino National Forest portion of the east San Gabriel’s was often referred to as the San Bernardino Mountains, in the 1800 hundreds and early 1900 hundreds. This made the determination of Cajon Pass locations even more difficult, as there were two Cajon Passes and Cajon Summits after 1860. One in the San Gabriel Mountains and one in the San Bernardino Mountains. Although the San Gabriel Mountain Cajon Pass was also referred to by may during the early years as being in the San Bernardino Mountains. During the 1800 and early 1900’s, the entire San Gabriel Mountain Range was commonly referred to as the San Antonio Mountains and less commonly, the Sierra Madre Mountains. The Sierra Madre Mountain reference may have been more in use for the western portion of the San Gabriel Mountains.

Cajon Pass:
When Cajon Pass is listed without any further description, a second date and location is also given, since it is uncertain whether the location refers to the San Gabriel Mountains or the San Bernardino Mountains. Up until 1860, the Cajon Pass route turned to the east, near the present day Cajon Junction at Highway. 138 and I-15 Freeway and passed through the San Bernardino Mountains through Summit Valley. If Cajon Summit is indicated prior to 1861, it is in the San Bernardino Mountains. at the west end of Horsethief Canyon and Summit Valley. Even if upper Cajon Pass is indicated on plant voucher data-labels, it’s still uncertain if the location is below or above the Cajon Junction, which is the separating point for the two upper routes.

Between 1861 and 1875, a new route went northward near the present course today. During this time it was a toll road. By 1875, the toll road was in disrepair. In 1882, the charter for the Toll Road expired and the route became public. If the upper Cajon Pass or Cajon Summit was referred to after 1861, it may have been in either the San Gabriel or San Bernardino Mountains, since there were now two Cajon Summits and two Cajon Passes. Between 1861 & 1875, the northern route would most likely have been referred to as the Cajon Toll Road. In the early years, the toll was one dollar per wagon. Locations after 1861 need to be examined for further detail to determine which Cajon Pass or Cajon Summit is being referred to. Regardless of the date, just the reference to Cajon Pass, does not indicate whether it was the southern portion, shared by both routes, or the upper portion, which now had a north and east branch. One was in the San Gabriel Mountains and the other in the San Bernardino Mountains Technically, most of the northern route, runs between the two mountain ranges and finally terminates at the summit on the San Gabriel Mountain side. The lower portion of the northern route could be placed in either mountain range, knowing that it actually lies in between them both.

At the dawn of the 20th Century, and the automobile, the Cajon Pass Road continued to remain in service. It was now a macadam-surfaced road and was maintained by the county of San Bernardino. In 1915, the Cajon Pass was adopted as a state Highway by the State Highway Commission and designated as part of Legislative Route # 31. The route was paved in 1916 and was open for general automotive traffic. It was adopted as pat of the new National US Highway. 66 and an original US Highway in 1926.

The paved route was then expanded into a new two-lane Cajon Pass Route in 1932 and was co-signed with the extended US Highway. 395 after 1934. It became US Highway 91 in 1947. The 1932 road persists today as the south-bound lanes of the northern Cajon Blvd. or Cajon Pass, the remnant of US 66/US 91/US 395, before the construction of the I-15 Freeway in 1969.

The above information regarding Cajon Pass, was taken from:

US 66, 91, 395 Photo Gallery: Cajon Pass, copyright 2004-2010-Cameron Keiser
http://www.gbcnet.com/ushighways/us395/395 pics 3.html or ...4.html
Casey@gbcaet.com.