Plant Guide to Ernie Maxwell Scenic Trail, San Jacinto Mountains

Introduction and Explanation of Plant Trail Guides

Highlights of This Trail
Fieldwork Dates and Summary of List Changes With Time
The Plant Guide
Comments On Specific Species


The Ernie Maxwell Scenic Trail is a beautiful and very popular trail from the bottom of Humber Park in Idyllwild to a rather unglorious end at the dusty non-scenic dirt road of Tahquitz View Drive just north of the turnoff to the South Ridge Trailhead.

The trail itself is indeed scenic, primarily for the views of the plants and rocks along the trail, but it also has a few views to the west that extend to the ocean. One might expect to see lots of views of the nearby homes all along the trail, but that doesn't happen; one feels surrounded by forest all the time. Most of the human traces along the way are large numbers of piles of twigs, branches, and cut-up dead trees stacked for burning in the wet season.

The trail is completely shaded for perhaps 80% or so of its length, with scattered regular shade in the remaining 20% of the trail. The openings in the forest have their own suite of delightful species; many of these areas must be absolutely beautiful with bloom in years when it rains.

The trail traverses a number of delightful drainages, but there is a bittersweet tinge to many of them that are probably only shadows of what they once were. Nearly every moist side drainage has a pipe carrying the precious water away from the plants and animals.

New species are encountered regularly along the trail, despite the trail staying in a fairly narrow range of elevation, and staying mostly with the same west-facing slope. This is very different from a similar trail at higher elevation, such as the PCT from Devils Slide to the South Ridge Trail, which is very depauperate in the total number of species. This difference is probably mainly due to the elevation, with the sunnier more open spots here having some chaparral species, whereas at higher elevation there is no chance of those chaparral species sneaking in there.

Many of the species found here are those also seen on the lower South Ridge Trail, which makes sense since the lower part of the two trails are only ~0.4 miles and ~900 feet of elevation apart. It is in fact quite interesting to be hiking directly below and almost parallel to that trail.

No permit is required to hike this trail, since it does not enter the San Jacinto Wilderness. An Adventure Pass is required to park within Humber Park, but parking spaces just outside Humber Park are about the same distance away from the upper trailhead, and do not require a Pass.

The trail is 2.3 miles one way, 4.6 miles round-trip, with ~750 feet of elevation gain and loss for the round-trip. (I computed 720 feet of gain and loss from all stretches with noticeable change in elevation, and rounded it up to 750 feet to include the imperceptible ups and downs on the trail.) The trail is nearly flat for the first 0.65 miles below Humber Park with an elevation change of only 100 feet, a rate of just 150 feet per mile. The trail then descends 220 feet to mile 1.06 at the rate of about 500 feet per mile. The trail is then again nearly flat to mile 1.5. The last 0.9 miles of the trail descends 380 feet at the rate of 430 feet per mile.

If you would like a shorter less-strenuous trip, hiking to mile 1.52 and back is 3.0 miles roundtrip, with just 350 feet of elevation gain and loss, and you'll only miss one of the on-trail (numbered) species on the trail, and six of the off-trail species.

Note that the two most popular guidebooks incorrectly state the elevation gain of this trail, which is hard to understand since the trail is clearly shown on the USGS topographic map. Robinson and Harris (2006) give 300 feet as the total gain for the one-way trip from the bottom to the top; the actual gain is a minimum of 700 feet.

Ferranti and Koenig (2000) apparently never give the actual elevation gain and loss along a trail in their guidebook, only the elevation difference between the bottom and top. This is a very unusual and misleading way to report it, especially since they call it the elevation gain. (I.e., if they reported their version of elevation gain for a hike from the North Rim of the Grand Canyon down to the bottom and then up the South Rim, they would report an elevation gain of zero feet, despite there being a true elevation gain of nearly one mile along that route!) They only give 300 feet for the elevation difference between the bottom and top; the actual difference is 6400 - 5720 = 680 feet.

For photographs of some of the plants in bloom on 22 May 2009, see Pictures From Ernie Maxwell Scenic Trail, San Jacinto Mountains, 22 May 2009.

Highlights of This Trail

This section not updated since 2009.

The botanical highlights of this trail are:

Number of Unique Taxa On This Trail

The following histogram gives the number of trails in our database that contain each taxon on this trail (not including the taxa seen only off-trail given at the end of the guide). We had 147 trails in our database when this histogram was made; 11 of those trails, including this one, are in the west side or south side of San Jacinto Mountain, with an additional 12 trails at higher elevation at San Jacinto Mountains. A number of "1" means the taxon has only been found on this trail among the trails in our database; numbers of "11" or smaller may indicate taxa found only in this area of San Jacinto Mountain.

Number of Trails
Containing A Taxon
Number Of Taxa
On This Trail
% of Taxa
On This Trail
Total Taxa94100%

We found 5 additional species not in the above table, since they have not been identified yet. The unidentified ones are marked with ? or sp in the id? column in the guide, and have no entry in the #all column.

Fieldwork Dates and Summary of List Changes With Time

This section not updated since 2009.

The following table gives the dates the trail was walked and taxa recorded. After each visit, the table gives the total number of taxa on the list and the breakdown of the taxa without positive identification. See Explanation of Plant Trail Guides to understand the symbols below.

Visit DateVisit ## taxa# "?"# "sp"# "~"# "ssp"

The Plant Guide

See Plant Checklist For Ernie Maxwell Scenic Trail for a list of the species in the guide below in traditional family order, including links to the Jepson eFlora and Calphotos.

For photographs of some of the plants in bloom on 22 May 2009, see Pictures From Ernie Maxwell Scenic Trail, San Jacinto Mountains, 22 May 2009.

The mileages in the guide come from Topo! and a GPS recording of the trail made on 29 May 2015, and should be differentially accurate to ~0.01-0.02 miles. The total mileage of the trail is probably a bit longer than the 2.29 miles given in the guide, but is probably less than the 2.35 miles from the GPS track, which includes GPS jitter between each point.

See Explanation of Plant Trail Guides for an explanation of the column headers.

This plant guide is in the 2012 Jepson Manual Second Edition system. The abundances given in this guide, in the column with header #Pls, reflect the total abundance of each species in the area around the trail, not just for the number of plants immediately along the trail. It also numbers species that are not immediately along the trail, as long as one can easily access them.

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MileS#id?Common NameScientific Name#Pls
0.00rBeginning of trail at Ernie Maxwell sign; 6400 feet (1951 m) elevation.
0.00l(incense-cedar mistletoe, Phoradendron juniperinum)
0.00r1incense-cedarCalocedrus decurrens99 / 9
0.00r2ponderosa pinePinus ponderosa var. pacifica50 / 9
0.00r(snow-plant, Sarcodes sanguinea)
0.00b3California black oakQuercus kelloggii99 / 9
0.00r4Sierra Nevada lotusAcmispon nevadensis var. nevadensis99 / 9
0.01lJct. shortcut use trail from south end of parking area
0.01r5canyon live oakQuercus chrysolepis99 / 9
0.01l(white fir, Abies concolor)
0.02r6bristly bird's beakCordylanthus rigidus ssp. setiger99 / 9
0.02rJct. use trail to road
0.02r7broad-leaved lotusHosackia crassifolia var. crassifolia35 / 3
0.02b8white firAbies concolor75 / 9
0.02r9fir mistletoePhoradendron bolleanum2 / 2
0.03r(sugar pine, Pinus lambertiana)
0.06lJct. another shortcut use trail from south end of parking area
0.08r10western azaleaRhododendron occidentale75 / 2
0.08l(pinedrops, Pterospora andromedea)
0.09r11mountain pink currantRibes nevadense99 / 5
0.09b(thimbleberry, Rubus parviflorus)
0.09b12white alderAlnus rhombifolia3 / 2
0.09Cross moist creek, the drainage from most of the area south of Saddle Junction and north of Lily Rock / Tahquitz Peak
0.09r13thimbleberryRubus parviflorus99 / 2
0.09l14sugar pinePinus lambertiana50 / 9
0.10r(bracken, Pteridium aquilinum var. pubescens)
0.11r15pinedropsPterospora andromedea4 / 1
0.13Trail turns left 90°
0.14b16Grinnell's beardtonguePenstemon grinnellii var. grinnellii35 / 2
0.14l(mountain whitethorn, Ceanothus cordulatus)
0.15r(common bedstraw, Galium aparine)
0.15r17mountain whitethornCeanothus cordulatusdead4 / 2
0.18lJct. “Climber's Trail” to Lily Rock
0.18r(*downy brome, Bromus tectorum)
0.18l18forest sedgeCarex multicaulis75 / 9
0.18l19green miner's lettuceClaytonia parviflora ssp. viridis99 / 2
0.18r20Jones' prickly-nut cryptanthaCryptantha muricata var. jonesii20 / 9
0.19b21common bedstrawGalium aparine35 / 3
0.19b22Laguna Mtns. jewel-flowerStreptanthus bernardinus30 / 2
0.19l23beautiful hulseaHulsea vestita ssp. callicarpha27 / 2
0.19l(western wallflower, Erysimum capitatum var. capitatum)
0.24l24Coulter pinePinus coulteri30 / 9
0.24lJct. use trail
0.27l25mountain rock-cressBoechera retrofracta X+20 / 5
0.28l26June grassKoeleria macranthadead99 / 9
0.29lJct. use trail
0.29r(pink-bracted manzanita, Arctostaphylos pringlei ssp. drupacea)
0.29b27San Jacinto buckwheatEriogonum apiculatum80 / 2
0.29b28naked buckwheatEriogonum nudum var. pauciflorum99 / 9
0.29b29squirreltailElymus elymoides50 / 9
0.29l30spgroundsmokeGayophytum sp.4 / 2
0.29l31mountain red-root cryptanthaCryptantha micrantha var. lepida99 / 5
0.29l32splendid giliaSaltugilia splendens ssp. splendens70 / 3
0.29l33plain mariposa lilyCalochortus invenustus99 / 9
0.30r34Fremont's goosefootChenopodium fremontii2 / 1
0.33Cross very small drainage
0.3335spotted coralrootCorallorhiza maculata15 / 3
0.35Cross very small drainage
0.36b36pink-bracted manzanitaArctostaphylos pringlei ssp. drupacea99 / 9
0.36l37oak mistletoePhoradendron serotinum ssp. tomentosum99 / 3
0.36l(southern mountain woolly-star, Eriastrum densifolium ssp. austromontanum)
0.36r38short-flowered monardellaMonardella nana99 / 9
0.36r?(plant with two leaves that are 2 ternate like celery, Apium_graveolens, or sweet-cicely, Osmorhiza sp.)
0.36l39wild sweetpeaLathyrus vestitus var. vestitus99 / 9
0.36l40western wallflowerErysimum capitatum var. capitatum60 / 3
0.36b41Wright's buckwheatEriogonum wrightii var. membranaceum99 / 9
0.36l42California-asterCorethrogyne filaginifolia40 / 9
0.37b43mountain grape-soda lupineLupinus excubitus var. austromontanus99 / 9
0.37r44Parish's tauschiaTauschia parishiidead61 / 9
0.38b45white catch-flySilene verecunda80 / 9
0.38r46mountain mugwortArtemisia ludoviciana ssp. incompta10 / 1
0.38r(golden yarrow, Eriophyllum confertiflorum var. confertiflorum)
0.41l47California bromeBromus carinatus var. carinatus10 / 3
0.41l48leafy daisyErigeron foliosus var. foliosus99 / 9
0.41r49American vetchVicia americana ssp. americana30 / 5
0.42l50goldenrodSolidago velutina ssp. californica99 / 5
0.42l51white hawkweedHieracium albiflorum17 / 2
0.44l52golden yarrowEriophyllum confertiflorum var. confertiflorum99 / 9
0.44l53Martin's paintbrushCastilleja applegatei ssp. martinii30 / 9
0.45l54slender everlastingPseudognaphalium thermaledead14 / 3
0.47l55strigose lotusAcmispon strigosus30 / 4
0.49Cross small drainage
0.49l56narrowleaf bedstrawGalium angustifolium ssp. angustifolium70 / 9
0.50l57showy bajada lupineLupinus concinnus ssp. optatus99 / 3
0.50l58southern mountain woolly-starEriastrum densifolium ssp. austromontanum50 / 5
0.50r59snow-plantSarcodes sanguinea1 / 1
0.52l60mountain California-fuchsiaEpilobium canum ssp. latifoliumdead99 / 5
0.60Cross dry drainage from southwest side of Lily Rock
0.65Trail begins to descend more steeply; elevation ~6300 feet (1920 m)
0.67l61Yosemite rockcressBoechera repandadead36 / 5
0.67rJct. trail probably leading to road just below; stay left
0.71Enter forest of oak mistletoe, Phoradendron serotinum ssp. tomentosum, for 0.01 miles
0.72l(San Bernardino rubber rabbitbrush, Ericameria nauseosa var. bernardina)
0.73Leave dense continuous forest; forest now interspersed with sunny open areas
0.77b62interior live oakQuercus wislizeni var. frutescens30 / 5
0.79l63*downy bromeBromus tectorum99 / 9
0.80l(oracle oak, Quercus Xmorehus)
0.82b64small fescueFestuca microstachys40 / 3
0.82l65pine dwarf-mistletoeArceuthobium campylopodum2 / 2
0.82l66white-margined oxythecaSidotheca emarginata99 / 2
0.83l(southern honeysuckle, Lonicera subspicata var. denudata)
0.84b67California elegant rock-cressBoechera californica20 / 5
0.84r68southern honeysuckleLonicera subspicata var. denudata2 / 2
0.85l69whisker-brushLeptosiphon ciliatus99 / 9
The following species was found farther along the trail, but without a precise location
?70sticky lessingiaLessingia glandulifera var. glandulifera1 / 1
0.87l(California cliff-brake, Pellaea mucronata var. californica)
0.9071silky lotusAcmispon heermannii var. heermannii2 / 1
0.91l72Davidson's buckwheatEriogonum davidsonii99 / 1
0.92l73hybrid manzanitaArctostaphylos patula X A. pringlei ssp. drupacea1 / 1
0.92Cross drainage
0.93l74little prince's pineChimaphila menziesii19 / 2
0.97Switchback left at ridge; elevation ~6100 feet (1859 m)
0.99Cross moist drainage from Tahquitz Peak which was scoured nearly clean of vegetation and covered in white sand/gravel in summer 2008 from a thunderstorm. Three lemon lilies, Lilium parryi, are up that drainage, not visible from the trail, along with subarctic lady-fern, Athyrium filix-femina var. cyclosorum
0.99l(western columbine, Aquilegia formosadead )
1.03b75spreading dogbaneApocynum androsaemifolium99 / 2
1.06Trail levels off; elevation ~6080 feet (1853 m)
1.15r76pine cryptanthaCryptantha simulans50 / 9
1.18l77blue dicksDichelostemma capitatum ssp. capitatum20 / 4
1.18Cross dry drainage
1.18l78volcanic giliaGilia ochroleuca ssp. exilis99 / 9
1.18l79annual phloxMicrosteris gracilis99 / 4
1.18l80diamond-petaled clarkiaClarkia rhomboidea99 / 9
1.20l81red-stemmed miner's lettuceClaytonia rubra ssp. rubra99 / 5
1.21r(woodland star, Lithophragma affine)
1.21r82California thistleCirsium occidentale var. californicum3 / 1
1.2283oracle oakQuercus Xmorehus2 / 2
1.22lfield of plain mariposa lily, Calochortus invenustus
1.22l84spear-leaved mountain dandelionAgoseris retrorsa50 / 9
1.22b85*garden trumpet daffodilNarcissus hybrid99 / 1
1.23r(Large water tank)
1.23l86incense-cedar mistletoePhoradendron juniperinum1 / 1
1.23r87imbricate phaceliaPhacelia imbricata var. patula75 / 1
1.31b88brackenPteridium aquilinum var. pubescens20 / 2
1.31Cross moist drainage coming from base of upper switchbacks on South Ridge Trail; minor local low point; elevation ~6080 feet (1853 m)
1.31b89Parish's burning bushEuonymus occidentalis var. parishii16 / 1
1.31b90sticky cinquefoilDrymocallis glandulosa var. viscida99 / 4
1.31l91Parish's lupineLupinus latifolius var. parishii40 / 3
1.31r92western columbineAquilegia formosa3 / 3
1.31r(California wild rose, Rosa californica)
1.35r93musk monkeyflowerMimulus moschatus20 / 1
1.35l(Durango root, Datisca glomerata in distance)
1.35l94California coffeeberryFrangula californica1 / 1
1.35Cross moist drainage coming from small saddle / level section of South Ridge Trail at 7600 feet elevation on that trail.
1.35r95~common monkeyflowerMimulus guttatus1 / 1
1.35r96floriferous monkeyflowerMimulus floribundus20 / 1
1.35r(fragile sheath sedge, Carex fracta)
1.3997woodland starLithophragma affine75 / 5
1.41b98spreading larkspurDelphinium patens ssp. montanum10 / 1
1.42Minor local high point; elevation ~6100 feet (1859 m)
1.42r99clustered broomrapeOrobanche fasciculatadead1 / 1
1.46l100Parish' Jacumba milk-vetchAstragalus douglasii var. parishii10 / 4
1.46l101scattered blazing starMentzelia dispersa10 / 1
1.48l102*prickly sow thistleSonchus asper ssp. asper1 / 1
1.50Cross small dry drainage; elevation 6000 feet (1829 m)
1.62l103birch-leaf mountain-mahoganyCercocarpus betuloides var. betuloides1 / 1
1.66rJct. steep path down to road below with deep roadcut
1.66l(rock goldenbush, Ericameria cuneata var. cuneata in distance)
1.67l104rock goldenbushEricameria cuneata var. cuneata2 / 1
1.73Cross drainage
1.73l105Scouler's willowSalix scouleriana1 / 1
1.82l106goldenstarBloomeria crocea10 / 2
1.88l(mountain piperia, Piperia transversa)
1.89l107California chicoryRafinesquia californica2 / 2
1.91l108mountain piperiaPiperia transversa20 / 2
1.94l109fragile sheath sedgeCarex fracta2 / 2
1.94r110California wild roseRosa californica12 / 1
1.94Cross moist drainage; elevation 5800 feet (1768 m). There are lemon lilies, Lilium parryi, downstream in this drainage, not visible from the trail
2.00l(way off-trail: Mexican manzanita, Arctostaphylos pungens)
2.07l111southern Chinese housesCollinsia concolor99 / 1
2.08r112blue wildryeElymus glaucus2 / 1
2.10r(stream orchid, Epipactis gigantea, not visible from the trail, at seep halfway down to Tahquitz View Drive, the road below the trail)
2.11r113curve-flowered skullcapScutellaria siphocampyloides50 / 1
2.17Cross dry drainage below spring just north of South Ridge Spring
2.17r114*garden pyracanthaPyracantha coccinea1 / 1
2.17b115Durango rootDatisca glomerata10 / 2
2.25l116leafless wintergreenPyrola aphylla1 / 1
2.29End trail at Tahquitz View Drive 0.9 miles north of the turnoff to the South Ridge Trailhead; elevation 5720 feet (1743 m); return the way you came
Species only found off-trail
0.72117San Bernardino rubber rabbitbrushEricameria nauseosa var. bernardina1 / 1
0.87118California cliff-brakePellaea mucronata var. californica1 / 1
0.99119lemon lilyLilium parryi3 / 1
0.99120subarctic lady-fernAthyrium filix-femina var. cyclosorum2 / 1
2.00121Mexican manzanitaArctostaphylos pungens1 / 1
2.10122stream orchidEpipactis gigantea99 / 1

Comments On Specific Species

Arabis holboellii. Unfortunately, this isn't the appropriate name for these plants, but there is no binomial name currently available for these plants. See Recent Changes in Delineation of These Species for more information.

Dead. The first plant seen of each of these species in 2007 through 2009 was dead in 2015. The first live plant of those species in 2015 is not noted in the guide. All the species are found later on the trail except for the Orobanche fasciculata, which was previously found as only a single plant.

We thank Adrienne Ballwey, Kate Harper, Jim Roberts, and Elize Van Zandt for help with the 29 May 2015 survey. Adrienne found the only plants of California cliff-brake, Pellaea mucronata var. californica. We thank Harry Spilman for help with the 5 June 2018 survey.

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Copyright © 2007-2018 by Tom Chester, Dave Stith, Nancy Accola, and Bruce Watts.
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Updated 20 June 2018