Flora of San Jacinto Peak Area, San Jacinto Mountains

Field Surveys
Procedure For Compiling The Checklist
Important Caveats
Analysis of the Flora
     Checklist in Jepson Manual 2 family order
     Checklist in order of the maximum elevation for each species
Taxa Rejected From The Checklist


San Jacinto Peak is the tallest peak in the San Jacinto Mountains, reaching a peak elevation of 10,842 feet (3,305 m). It is an unusual peak for the high mountains of southern California, since it stands on top of the roughly-pyramidal-shaped San Jacinto Mountains. All other high peaks in southern California are the high points along ridges, since they have been uplifted by linear faults. The San Jacinto Mountains are different because they are the uplifted wedge near the junction of the two most prominent faults in southern California, the San Jacinto and San Andreas Faults. San Jacinto Peak stands close to the point of the wedge.

As a result, the views from the peak are extensive, since the Peak stands well above the surrounding terrain in almost all directions. In particular, the northern slope of San Jacinto Mountain drops an amazing 9,682 feet in only 5.85 miles (2,951 m in 9.41 km), to 1,160 feet in Snow Canyon, a gradient of 1,655 feet per mile (314 m per km). The average slope over this entire distance is 31%; the uppermost slope averages an amazing 75% in the first 0.92 miles, a drop of 3,642 feet in 0.92 miles (1,110 m in 1.48 km).

Willis Lynn Jepson wrote in his botanical field journal on August 9, 1903:

From the summit of San Jacinto one has to my notion the finest outlook for unstudied comprehensiveness in all of California. One can see great distances in every direction. The mountain ranges succeed one another northeastward but one can not only overlook them but detect the vast mesas and desert plains which lie between them. And the highest range in the distance which finally shuts out the view is so far away that it gives no sense of dissatisfaction or complicating of a problem which one desires to solve as in the case of a range near at hand closing the immediate view as in the Sierras. Everything is understandable, comprehensible, to be worked out readily with the eye. We could name road, trail and mountain by aid of the contour map as readily as if the letters were spelled large on the country.

The different origin of San Jacinto Peak also leads to it having a very different flora on top than Mt. San Antonio (Mt. Baldy) in the San Gabriels and Mt. San Gorgonio (Old Greyback) in the San Bernardinos. Both of those other peaks are above their treeline, with extensive flattish ridges that are highly rounded tranversely to the ridges, populated mostly by low-growing matted plants. San Jacinto Peak is not noticeably different in its flora than its surroundings, with the same tall trees and normal-height shrubs found all around it. A photograph of the top of San Jacinto Peak would never be mistaken for a photograph of the top of Baldy or Old Greyback! See Fig. 1 for a comparison of Baldy with San Jacinto Peak.

Fig. 1. Top: view of the Folly Peak / San Jacinto Peak ridgeline from the west. Note the extensive tree cover except for the precipitous north slope on the left and on minor rock outcrops. Bottom: view of the Mt. Baldy / West Baldy ridgeline from the north. Each set of peaks is about 0.5 miles apart. Note that Mt. Baldy is aptly named, with no trees present near the ridgeline, even on the north-facing slope shown here. Mt. Baldy also has a flatter profile and a more gently rounded ridgeline.

Although it is often said that San Jacinto Peak is the second tallest peak in southern California, that is not correct. The San Bernardino Mountains contain six taller peaks, thus San Jacinto Peak is actually the seventh tallest peak in southern California. However, most people would agree that San Jacinto Peak is the second most prominent peak in southern California, overshadowed only by Mount San Gorgonio, and the San Jacinto mountain range is indeed the second-highest mountain range in southern California.. For more information, see The Elevation and Prominence of San Jacinto Peak.

This page gives the flora of the entire San Jacinto high country above 10,000 feet elevation, which includes six peaks that are either named, or given an elevation of their high point on the topo map, and three other unnamed peaks. This high country is mostly a separate floral unit, fairly distinct from the slopes and valleys surrounding it since it is somewhat flattish on top, with steep slopes along the edges at 10,000 feet. Below 10,000 feet, one is clearly in an area associated with a given side of the mountain (north / south / east / west), often with a named valley. Above 10,000 feet, the orientation of the land is most toward the sky.

There are only 32 species that have been recorded in this area above 10,000 feet. Of those, 27 have been recorded in the immediate vicinity of San Jacinto Peak.

San Jacinto Peak, like all high peaks, has been a magnet for botanists. Of the 27 species found in the immediate vicinity of the Peak, 25 (93%) have a voucher from the Peak itself and many of these species have multiple vouchers from there. For comparison, of the 51 species found in the Hidden Lake Drainage Area, 39 of them (76%) have a voucher from that area, and that area is also a magnet for botanists.

The species without vouchers in the immediate vicinity of San Jacinto Peak, with their highest elevation from vouchers, are Epilobium canum ssp. latifolium (8000 feet), and Galium parishii (8900 feet). The next highest location from our observations of Epilobium canum ssp. latifolium is 9550 feet at Cornell Peak.

The other peaks of the high country have not been visited by collectors; there are only two vouchers from this area except near San Jacinto Peak or on the trail to San Jacinto Peak, both from Jean Peak.


This section has not been updated yet.

The following map shows the location of San Jacinto Peak and the floral area targeted here:

Fig. 2. Map showing the area of San Jacinto Mountain above 10,000 feet elevation, outlined with the purple contour, and the six surveys labeled 1 through 6 from north to south shown in various colors..

The main ridgeline of the San Jacinto high country runs 2.2 miles north-south, and contains five peaks: Folly Peak, San Jacinto Peak, Jean Peak, "Shirley" Peak, and Marion Mountain. These peaks all have similar elevations, with a maximum difference of just 480 feet. In the same order, the elevations are ~10,500; 10,842; 10,670; 10,388; and 10,362 feet. The minimum elevation of the saddles between the northern peaks is 10,400 feet, decreasing to 10,200 feet at the southernmost saddle. The width of the flattish part of the ridgetop is ~1 mile on the north, from Folly Peak to Miller Peak, and about a half mile on the south.

Field Surveys

Details on the six field surveys are given in Table 1.

Table 1: The Six Field Surveys

#         Date         LocationElevation Range (feet)# of
112 August 2007
3 July 2008
27 June 2013
Trail from Wellman Divide to San Jacinto Peak10,000 - 10,84029Tom Chester, Aaron Fellows, Anne Kelley, Cliff McLean, Gabi McLean, Walt Fidler, Eric Baecht
216 August 2010Junction Deer Springs Trail to Folly Peak 10,420 - 10,59017Tom Chester, Dave Stith, James Dillane, Pam Pallette
330 July 2010Upper Deer Springs Trail to 10,120 feet10,000 - 10,1206Tom Chester, Dave Stith
48 August 2012Jean Peak area10,100 - 10,6709Tom Chester, Dave Stith
530 July 2012Marion Mountain Saddle Area to Poachers Camp10,000 - 10,17010Tom Chester, Dave Stith
626 July 2012Marion Mountain Saddle Area to the real Deer Springs10,000 - 10,12010Tom Chester, Dave Stith, Bob Hepburn

The species found on each of six surveys are given in Table 2. The minimum number of plants is given for all surveys except for #5, where no field estimates were made.

Table 2: Number of Plants found in Each Field Survey

#FamilScientific NameSurvey Number
1Selag Selaginella watsonii4099 99  
2Pteri Cryptogramma acrostichoides 2    
3Woods Cystopteris fragilis125 25  
4Pinac Pinus contorta ssp. murrayana9999x999999
5Pinac Pinus flexilis1050x502020
6Apiac Sphenosciadium capitellatum1     
7Aster Ericameria nauseosa var. bernardina11     
8Brass Draba saxosa110    
9Capri Symphoricarpos rotundifolius var. parishii99     
10Caryo Silene parishii5535    
11Fabac Lupinus hyacinthinus9999x 9999
12Fagac Chrysolepis sempervirens9999x209999
13Gross Ribes cereum var. cereum9910 2  
14Gross Ribes montigenum102 39999
15Lamia Monardella australis var. australis99     
16Monti Calyptridium monospermumx3  9910
17Onagr Epilobium canum ssp. latifolium5     
18Oroba Castilleja applegatei ssp. martinii2     
19Oroba Pedicularis semibarbata199    
20Polyg Oxyria digyna1     
21Ranun Ranunculus eschscholtzii var. oxynotus2     
22Rosac Holodiscus discolor var. microphyllus535  1 
23Rubia Galium parishii10     
24Saxif Heuchera hirsutissima5050    
25Cyper Carex fracta  x   
26Cyper Carex heteroneura    9930
27Cyper Carex rossii155x20410
28Cyper Carex subfusca9999 109999
29Poace Agrostis idahoensis     99


This section not written yet.

Key points to be added in the future in the text:

Procedure For Compiling The Checklist

The Checklist was updated on 26 June 2013, from a number of later field surveys, and the vouchers were reexamined. But the text below has not yet been updated.

The Checklist was compiled by the first author from online vouchers, from Hall's 1902 Flora of San Jacinto Mountain, and from field work done on 3 July 2008 (by all authors) and on 12 August 2007 (by a subset of the authors).

The vouchers were obtained in five ways:

The species list from the vouchers was then culled to remove species names that probably do not exist at San Jacinto Peak, either because the location was not precise enough to be sure that the voucher was taken from the targeted area, or because the species determination on the voucher was unlikely to be correct. The rejected species are detailed below.

The above procedure resulted in a list of 26 species from vouchers.

The field work on 3 July 2008 and on 12 August 2007 resulted in a list of 18 species, including three species not found in the voucher list, creating a total list of 29 taxa. The additional three species are vouchered from nearby areas; just not from the specific area targeted here.

Important Caveats

Please note the following important caveats about this preliminary Checklist:

Analysis of the Flora

Give overview of the flora; dominant plants in different areas; disjuncts, including the two alpine species; etc. Comparison of the flora to SnGb and SnBr, and Sierra Nevada.

Checklist for San Jacinto Peak

The Checklist is given twice, first in Jepson Manual 2 family order, and then in order of the maximum elevation for each species.

The Checklist follows the Jepson Manual Second Edition with only a few exceptions. It is sorted first by category and then by family and scientific name. The family name is abbreviated to the first five characters in order to save space in the table rows.

A few species have qualifiers given in front of the scientific name, indicating that the species determination is not 100%. Notes on many of those species are given in the next section.

An asterisk before the Common Name would indicate a non-native taxon, but all of the taxa found so far here are native.

The three columns under the header #Plants give a minimum estimate of the number of plants we saw along our entire survey in each area (up to a maximum of 99 plants). The southwest area (SW) is presented first, since its flora is significantly different from the other two areas, being dominated by chaparral. The other two areas, the north half of the park (N) and the southeast part of the park (SE), have significant riparian areas and are dominated by the pine forest.

The scientific name is linked to the latest online Jepson Manual description for each species, which also gives the months in which each species flowers. That link also gives a map of where the species occurs in California; a plot of elevation vs. latitude for California; and a histogram of the voucher collections by month. Only a few species will not have working links, if their names have been updated more recently (such as Mimulus diffusus, which is still listed under M. palmeri in the online flora, or if they are reserved-judgment taxa which are listed in the entry for another taxon name.

The common name for each species in the checklist is linked to Calphotos to give pictures of most taxa. Note that the link will not always return pictures, since not every species has pictures at Calphotos, and a number of species still have their Calphotos pictures under the Jepson Manual First Edition Names.

There are three columns that follow the names for each taxa:

See also the list of rejected species given below.

Version for printing, without lines and other text on this page: html (4 pages) or pdf Clickbook booklet (1 double-sided page). (See printing instructions for an explanation of these options)

Checklist in Jepson Manual 2 family order

#FamilScientific Name(*)Common NameMax
1SelagSelaginella watsoniiWatson's spike-moss10805993
2PteriCryptogramma acrostichoidesAmerican parsley fern1044021
3WoodsCystopteris fragilisbrittle bladder fern10805503
4PinacPinus contorta ssp. murrayanalodgepole pine10710996
5PinacPinus flexilislimber pine10840996
6ApiacSphenosciadium capitellatumranger's buttons1028011
7AsterEricameria nauseosa var. bernardinaSan Bernardino rubber rabbitbrush10500111
8BrassDraba saxosaSouthern California rock draba10805102
9CapriSymphoricarpos rotundifolius var. parishiiParish's snowberry10720991
10CaryoSilene parishiiParish's campion10800902
11FabacLupinus hyacinthinusSan Jacinto lupine10670995
12FagacChrysolepis sempervirensbush chinquapin10840996
13GrossRibes cereum var. cereumwax currant10600993
14GrossRibes montigenummountain gooseberry10840995
15LamiaMonardella australis var. australissouthern mountain-monardella10450991
16MontiCalyptridium monospermumpussy paws10670993
17MontiCalyptridium parryi var. parryiParry's sand cress10805V1
18OnagrEpilobium canum ssp. latifoliummountain California-fuchsia1080051
19OrobaCastilleja applegatei ssp. martiniiMartin's paintbrush1030021
20OrobaPedicularis semibarbatapine lousewort10510992
21PolygOxyria digynaalpine mountain-sorrel1082011
22RanunAquilegia formosawestern columbine10700V1
23RanunRanunculus eschscholtzii var. oxynotusEschscholtz's buttercup1082021
24RosacHolodiscus discolor var. microphyllusmountain spray10840403
25RubiaGalium parishiiParish's bedstraw10560101
26SaxifHeuchera hirsutissimashaggy-haired alumroot10800992
27CyperCarex fractafragile sheath sedge1000011
28CyperCarex heteroneuravari-nerved sedge10040992
29CyperCarex rossiiRoss' sedge10665556
30CyperCarex subfuscabrown sedge10840995
31PoaceAgrostis idahoensisIdaho bentgrass10040991
32PoaceTrisetum spicatumspike trisetum10800V1

Checklist in Declining Order of Maximum Elevation For Each Species

#FamilScientific Name(*)Common NameMax
1CyperCarex subfuscabrown sedge10840995
2FagacChrysolepis sempervirensbush chinquapin10840996
3RosacHolodiscus discolor var. microphyllusmountain spray10840403
4PinacPinus flexilislimber pine10840996
5GrossRibes montigenummountain gooseberry10840995
6PolygOxyria digynaalpine mountain-sorrel1082011
7RanunRanunculus eschscholtzii var. oxynotusEschscholtz's buttercup1082021
8MontiCalyptridium parryi var. parryiParry's sand cress10805V1
9WoodsCystopteris fragilisbrittle bladder fern10805503
10BrassDraba saxosaSouthern California rock draba10805102
11SelagSelaginella watsoniiWatson's spike-moss10805993
12OnagrEpilobium canum ssp. latifoliummountain California-fuchsia1080051
13SaxifHeuchera hirsutissimashaggy-haired alumroot10800992
14CaryoSilene parishiiParish's campion10800902
15PoaceTrisetum spicatumspike trisetum10800V1
16CapriSymphoricarpos rotundifolius var. parishiiParish's snowberry10720991
17PinacPinus contorta ssp. murrayanalodgepole pine10710996
18RanunAquilegia formosawestern columbine10700V1
19MontiCalyptridium monospermumpussy paws10670993
20FabacLupinus hyacinthinusSan Jacinto lupine10670995
21CyperCarex rossiiRoss' sedge10665556
22GrossRibes cereum var. cereumwax currant10600993
23RubiaGalium parishiiParish's bedstraw10560101
24OrobaPedicularis semibarbatapine lousewort10510992
25AsterEricameria nauseosa var. bernardinaSan Bernardino rubber rabbitbrush10500111
26LamiaMonardella australis var. australissouthern mountain-monardella10450991
27PteriCryptogramma acrostichoidesAmerican parsley fern1044021
28OrobaCastilleja applegatei ssp. martiniiMartin's paintbrush1030021
29ApiacSphenosciadium capitellatumranger's buttons1028011
30PoaceAgrostis idahoensisIdaho bentgrass10040991
31CyperCarex heteroneuravari-nerved sedge10040992
32CyperCarex fractafragile sheath sedge1000011

Taxa Rejected From The Checklist

This section has not been updated to include taxa rejected as of 26 June 2013.

Taxa Rejected Due To Uncertain Locations

The taxon name is linked to the online voucher record.

Hymenoxys acaulis var. arizonica, UC472678. There is only this single online voucher of this taxon in all of San Jacinto Mountain, from 9000-12000 ft; high mountain species, on grassy slopes, heavy soil. The elevation range is curious, since there are no elevations higher than 10,842 feet here, and the elevation of San Jacinto Peak has been well-known since before the year 1902. Furthermore, grassy slopes with heavy soil are non-existent in the area targeted here. Hence it is unlikely this voucher was collected from the area targeted here.

There is one other voucher from this year from this collector, and it has a note that it has an incorrect label. probably from Ariz.

Amelanchier utahensis, UC472696, also has the curious reported elevation of 9000-12000 ft, but the locality is given as Mt. Tahquitz - San Jacinto Mts., so it is surely not from the area of San Jacinto Peak. Tahquitz Peak has an elevation of 8,846 feet.

Taxa Rejected Due To Probably-Incorrect Determinations

Calyptridium umbellatum, JEPS52509. This voucher was apparently last determined in 1928. Prior to Hinton's study in 1975, many specimens of C. monospermum were lumped with C. umbellatum. The species in the San Jacinto Mountains is C. monospermum.

Spraguea umbellata, UC7765. This is a yet older name for Calyptridium umbellatum, and is probably just a databasing error, since it was annotated as Calyptridium monospermum in 1972 by W. F. Hinton.

Lupinus formosus var. formosus, RSA414785, and Lupinus formosus subsp. proximus, RSA442334. These vouchers are almost surely L. hyacinthinus, a very common and widespread species at San Jacinto Mountain, which is close to L. formosus and often confused with it.

Carex preslii, UC455134. This is the only voucher of "C. preslii" in southern California; the nearest other online specimen is from northern Inyo county, some 200 miles to the north. The most common Carex at high elevations at San Jacinto Mountain is C. subfusca, which is quite close to C. preslii according to the Jepson Manual key and descriptions. We chose not to include this name until we have further confirmation of its existence here.

Voucher data provided by the participants of the Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/). We thank Jane Strong for figuring out the word comprehensiveness in Jepson's handwriting for the quote above.

We thank the following people who each participated in one of the eight surveys, in alphabetical order: Eric Baecht, Brendan Crill, James Dillane, Aaron Fellows, Walt Fidler, Bob Hepburn, Anne Kelly, Cliff McLean, Gabi McLean and Pam Pallette.

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Copyright © 2008-2013 by Tom Chester and Dave Stith
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Last update: 1 July 2013