Historical Review of Plant Collecting in the San Gabriel Mountains
Los Angeles County Portion - exclusive of the Liebre Mountains
Los Angeles County

Dick Swinney
October 15, 2009

A Chronological Review - Introduction - LA 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 Mountain Study Area:
The main east-west block of this Mountain Range has been selected for the presentation of the flora within the Los Angeles County portion of the San Gabriel Mountains. A similar publication for the San Bernardino County Portion of the San Gabriel Mountains is also being prepared by the author. Discussion and explanation regarding the exclusion of the Liebre Mountain portion of this mountain range, 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 Gabriels, 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 to examining the sources of climatic differences.

Description of boundaries:
Northern boundary from west to east
Commencing at Santa Clara River in Soledad Canyon at Dry Creek and following Soledad Canyon to the east through Ravenna and east to Vincent. East to the junction of Fort Tejon Road and Little Rock Creek. Mount Emma Road to Fort Tejon Road, to 131 st. Street East. Due east, passing just north of Holcomb Ridge and continuing through the foothills north of Largo Vista. Continuing east in the San Gabriel Mountain foothills and slightly south to the San Bernardino County Line.
Western boundary from north to south
Santa Clara River at Dry Creek south to Newhall Creek at State Highway 14 and continue south along Newhall Creek to the south-facing foothills of the San Gabriel Mountains to the area just north of the I-210 Freeway.
Southern boundary from west to east
From Newhall Creek (north of junction of I-5 and I-210 Freeways, continue east through the foothill on the southern front of the San Gabriel Mountains to Big Tujunga Canyon. The boundary will dip below the I-210 Frwy to include the ponds east of Hansen Dam. This area lies between the Verdugo and San Gabriel Mountains. Continue ENE along the Big Tujunga River to the foothills north of Foothill Blue. and Mount Gleason Ave. junction. Continue ESE along the southern formation of foothills, always staying above (north of) the
housing developments, at the very southern edge of the foothill natural areas. Continue in this manner to the east until reaching the mouth of the San Gabriel River. This area has a strong undisturbed element as it flow southward. The wash area will be included south to the I-210 Frwy. The boundary will continue eastward, north of Sierra Madre Ave. and in the natural foothill areas of Glendora, San Dimas, LaVerne, Claremont, Pomona and Upland, until reaching the Los Angeles /San Bernardino County Line at San Antonio Canyon Debris Basin. The South Hill in the southern portion of Glendora will not be included as part of the San Gabriel Mountain system.
Eastern boundary from north to south
Northern point is in the desert foothills in southern area of the town of Pinyon Hills, north-east of Jubilee Boy Scout Camp, at the county line. The boundary runs south and slightly east to the western portion of East Mount Baldy (Mt. San Antonio). The county line continues south and veers slightly to the west until reaching San Antonio Dam, at the south-eastern corner of this study area.

Study Description and the California Consortium of Herbaria:
The list of plant species included here, have been compiled from the California Consortium of Herbaria data base of plants, found in the Los Angeles County portion of the San Gabriel Mountains, exclusive of the Liebre Mountains to the north-west. The Liebre’s are considered as part of the San Gabriel Mountains on most maps. The main east-west block of this mountain range has been selected for presentation for the scope of this study. Further discussion and explanation for emitting the north-western projection of the Liebre Mountains, will perhaps be entertained at a later time.

The California Consortium of Herbaria 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 listed in the CC of Herbaria will be listed here unless otherwise noted.

All plant names have been annotated when necessary to conform with the latest scientific names as presented by the USDA Plant Database - 2009, 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 subspecies (ssp.) names are referred to as the nominate subspecies. Some of these in fact simply may not have been determined to the subspecific level and may not in fact be the nominate nominate taxa. No attempt was made in this study to clarify the status of the nominate species.

The main focus of this study is to provide a comprehensive, although not a complete listing 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 elevations 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”, have been placed at the end.

The earliest date found for collected specimens for the Los Angeles County portion of the San Gabriel Mountains, exclusive of the Liebre Mountains, was 1860, by William H. Brewer. The earliest record for the San Bernardino portion, was much earlier, at 1824 by Marcus Jones. There are 1883 plant taxa included in this publication. This represents an inflated number, as many of the nominate species listed, most likely have not been determined to the subspecific level.

Placename discrepancies and location descriptions:

Several of the early collectors spelled Swarthout Valley without an h. This spelling was perhaps used on earlier maps. The spelling has been kept as it was used.

El Encanto in Azusa, San Gabriel Canyon, was originally a restaurant. The development and surrounding area has now become the El Encanto Wilderness Park.

Glendora Wilderness Park in Glendora, which was the name listed on some concession labels, is now called the Big Dalton Canyon Wilderness Park.

SDEF - San Dimas Experimental Forest, between Little Dalton Cyn. in Glendora and San Antonio Cyn., north of Upland.

In the past, the San Gabriel Mts. were commonly referred to as the San Antonio Mountains and the Sierra Madre Mountains.

Plants collected at New York Ave. by F.W. Peirson, had to be closely examined to determine whether they were collected in the irrigated property of Mr. Peirson. Others on New York Ave. were apparently in natural areas or disturbed places within natural areas.

Plants collected by L.C. Wheeler at or near 2 mi. n. of LaVerne, were often collected in irrigated orchards. These records were not use.

Plants collected by L.C. Wheeler at Blum Ranch in Santiago Cyn., were mostly collected in irrigated fields and were not used in the study. The agricultural nature of the data on the above three conditions, were not normally available in the general data description from the CC of Herbaria. The additional comments section had to be referenced.