Plant Guide to Devils Slide Trail, San Jacinto Mountains

Fig. 1.

Three members of the Ericaceae, heath family, and one member (Kopsiopsis strobilacea) of the Orobanchaceae, broomrape family, from the Devils Slide Trail.

Top Row:
Left: Rhododendron occidentale, western azalea, a species with a large, showy, very fragrant flower, photographed at mile 2.07 on 7 July 2008. This is the only non-parasitic plant in this group of four species. See also pix showing plants in bloom against a backdrop of Suicide Rock and Marion Ridge.
Right: Kopsiopsis strobilacea, California groundcone, a flowering plant that looks like a small pine cone unless it is in bloom and you look very closely at it, photographed at mile 2.14 on 7 June 2014. Here it is a parasite on the roots of Arctostaphylos patula, green-leaf manzanita.

Bottom Row:
Left: Sarcodes sanguinea, snow-plant, photographed at mile 1.42 on 7 June 2014. It is a parasite on fungi.
Right: Pterospora andromedea, pinedrops, photographed at mile 1.32 on 1 August 2019. It is a parasite on fungi. See Growth Rate and Bloom Time for these plants.

Click on the pictures for larger versions. Photographs by Tom Chester.

Introduction and Explanation of Plant Trail Guides

Botanical Highlights of This Trail
Botanical Trip Reports
The Plant Guide
Comments On Specific Species


The Devils Slide Trail is the premier trail in the Idyllwild area of the San Jacinto Mountains for a number of reasons:

The trail also is an excellent physical workout. The trail is 2.5 miles long, 5 miles roundtrip, with 1600 feet of elevation gain, an average gradient of 640 feet per mile. This is therefore a fairly steep trail, with an elevation gradient just slightly less than the 700 feet per mile of the upper three miles of the Bright Angel Trail in the Grand Canyon.

One downside of the high elevation is the lower amount of oxygen in the air. At 7500 feet, there is only ~80% of the amount of oxygen as at sea level. As a result, I can only go uphill at about 1.6 mph on this trail, compared to 2.5 mph on a similar trail at elevations below 3000 feet. But if you are botanizing the trail, you'll be going slow enough that the lack of oxygen won't affect you.

The trail begins in Humber Park two miles above the town of Idyllwild at the end of Fern Valley Road. A free wilderness permit, limited to 12 people per permit, is required for day use, and the number of permits is limited on summer weekend days and holidays. The permit is not available at the trailhead, and there are often rangers at the trailhead or along the trail checking permits on heavy use days. We have personally run into rangers checking permits on several different days. The permit can be picked up at the Forest Service office at 54270 Pinecrest, which is just east of SR243 in downtown Idyllwild.

An Adventure Pass is required to park at Humber Park. A day or yearly pass can be purchased at the Forest Service office or nearby merchants.

The following Google Earth views show the Trail and Tahquitz Valley, as seen from a vantage point over Idyllwild looking east, along with the distribution on the trail of the indicated species:

See also a picture of the Devils Slide Trail area taken from the Pacific Crest Trail at about 8900 feet just west of the Marion Mountain Ridge: with labels and without labels.

Botanical Highlights of This Trail

The botanical highlights of this trail are:

There are 137 species reliably found on this trail. One of those species has two subspecies here, making a total of 138 taxa on the trail. We have additionally found eight species that were waifs here, appearing only once or twice in our 17 years of surveying this trail.

Photographs of 83 species from this trail are at iNaturalist, 60% of the 138 taxa reliably found on the trail as of 5 July 2020. As of 15 September 2020, iNat has 436 observations from this trail by 49 different observers (note that iNat considers mosses as a plant, so their summary page reports more species than just the vascular plant species reported here).

Michael Charters has a two page photo gallery from this trail from May 2009

Nick Shah has two photo galleries from this trail, of plants in order as he hiked the trail on two Lemon Lily hikes led by Dave Stith, as part of the Idyllwild Lemon Lily Festival. Both hikes continued past the top of the Devils Slide Trail, so only photographs before the "Saddle Junction" sign are part of the Devils Slide Trail. See:

See also:

Botanical Trip Reports

Tom placed botanical reports online only in the early part of his career, until he ran out of time to continue putting them online after each trip. The following reports are from 2004 to 2007, even though we continued to botanize the trail in the next thirteen years:

10 April 2004
7 July 2006
10 July 2006
14 July 2006
19 July 2006
26 July 2006
2 August 2006
11 August 2006
16 August 2006
8 July 2007

The Plant Guide

See also Plant Checklist in Family Order for this trail.

This plant trail guide was begun on 30 June 2002, and in aggregate the authors have botanized and/or hiked this trail on 100 separate days as of 1 September 2020, a span of over 20 years. In addition, we very frequently have had sharp-eyed companions botanizing the trail with us, who have been responsible for finding species we had missed; see the list at the bottom of this page.

If you are using a GPS, either a stand-alone GPS or one on your camera or phone, note that there are often problems in getting an accurate position on this trail, due to dense tree cover, the restricted sky field of view caused by the mountain, and multipath GPS signal error caused by reflections off boulders. The GPS path reported by my Garmin eTrex, even in 2020, can be very different on the way down the trail than on the way up the trail. The mileages in the guide come from the consensus track from a large number of tracks.

See Explanation of Plant Trail Guides for an explanation of the column headers. This plant trail guide is slightly different. Since there are no uncertain determinations, there is no ID? column. The #Pls in this guide includes not just the number of plants on-trail, but those in the vicinity of the trail as well. The column #all is not given here.

See Notes on the Scientific Names Used At This Site.

Version for printing, without lines and other text on this page: html (7 pages) or pdf Clickbook booklet (2 double-sided pages). (See printing instructions for an explanation of these options)

MileS#Common NameScientific Name#Pls
0.00Beginning of trail in southeast corner of parking lot, to right of sign with introductory information; 6480 feet (1975 m) elevation.
0.00l1mountain whitethornCeanothus cordulatus99 / 9
0.00l2incense-cedarCalocedrus decurrens30 / 7
0.00Trail turns left 90°
0.01r3California black oakQuercus kelloggii30 / 7
0.01l4canyon live oakQuercus chrysolepis99 / 9
0.01b5ponderosa pinePinus ponderosa var. pacifica+50 / 5
0.01r6white firAbies concolor99 / 9
0.01l7sugar pinePinus lambertiana99 / 9
0.01rSign: San Jacinto Wilderness, San Bernardino National Forest
0.01lSign: "Be prepared for hazardous conditions beyond this point. Permit required beyond this point. Bikes are not permitted within the San Jacinto Wilderness or on the PCT"
0.03l8fir mistletoePhoradendron bolleanum99 / 9
0.04(incense-cedar mistletoe, Phoradendron juniperinum)
0.04b9Sierra Nevada lotusAcmispon nevadensis var. nevadensis40 / 2
0.04l10former first location of chaparral lotus, last seen here in [2005?]Acmispon grandiflorus var. grandiflorus20 / 2
0.04l11Indian milkweedAsclepias eriocarpa20 / 2
0.08rHuge boulder ~20 feet tall next to a huge dead white fir, showing how its trunk is made of wood spiraled around.
0.13r12Coulter pinePinus coulteri5 / 2
0.13l(pink-bracted manzanita, Arctostaphylos pringlei ssp. drupacea)
0.13Switchback right, #1.
0.15lfirst location of chaparral lotus, Acmispon grandiflorus var. grandiflorus, in 2011
0.15l13Davidson's buckwheat (waif)Eriogonum davidsonii+2 / 2
0.16l14snow-plantSarcodes sanguinea12 / 3
0.16l15splendid giliaSaltugilia splendens ssp. splendens25 / 4
0.17b16California-asterCorethrogyne filaginifolia+50 / 4
0.18l(narrowleaf bedstraw, Galium angustifolium ssp. angustifolium)
0.18l(Grinnell's beardtongue, Penstemon grinnellii var. grinnellii, gone in 2020)
0.18r17leafless wintergreen (appears only infrequently)Pyrola aphylla2 / 2
0.19r(oak mistletoe, Phoradendron serotinum ssp. tomentosum)
0.22l(forest sedge, Carex multicaulis)
0.23Switchback left, #2. Old trail continued down straight ahead.
0.24l18white-veined wintergreenPyrola picta5 / 2
0.24l19spotted coralrootCorallorhiza maculata10 / 4
0.25r20naked buckwheatEriogonum nudum var. pauciflorum30 / 3
0.25r21forest sedgeCarex multicaulis10 / 3
0.25r22prickly cryptantha (waif)Cryptantha muricata+4 / 2
0.31l23southern honeysuckleLonicera subspicata var. denudata5 / 5
0.33r24interior live oak (at northwest side of 10' boulder)Quercus wislizeni var. frutescens+4 / 1
0.36l25pinedropsPterospora andromedea17 / 6
0.37r26mountain grape-soda lupineLupinus excubitus var. austromontanus8 / 1
0.37r(beautiful hulsea, Hulsea vestita ssp. callicarpha)
0.37r27San Jacinto buckwheatEriogonum apiculatum+50 / 1
0.38r28golden yarrowEriophyllum confertiflorum var. confertiflorum10 / 1
0.38r29silky lotus (gone in 2020)Acmispon heermannii var. heermannii5 / 1
0.38r(California elegant rock-cress, Boechera californica)
0.39r30twiggy wreath plant (waifs)Stephanomeria virgata+2 / 2
0.40r(short-flowered monardella, Monardella nana, here and at mile 0.49)
0.46rpine died in August, 2006.
0.46r(beaked penstemon, Penstemon rostriflorus)
0.46r(California-fuchsia, Epilobium canum ssp. latifolium)
0.49l31pink-bracted manzanitaArctostaphylos pringlei ssp. drupacea30 / 5
0.49r32*downy bromeBromus tectorum+3 / 1
0.54l(San Bernardino rubber rabbitbrush, Ericameria nauseosa ssp. bernardina)
0.57l33Grinnell's beardtonguePenstemon grinnellii var. grinnellii99 / 6
0.60l34beaked penstemonPenstemon rostriflorus50 / 9
0.66b(Laguna Mtns. jewel-flower, Streptanthus bernardinus)
0.68Switchback right, #3; elevation 6900 feet (2100 m). Old trail continued up straight ahead.
0.69l35Laguna Mtns. jewel-flowerStreptanthus bernardinus10 / 2
0.76Switchback left, #4. A "mirror-image" switchback of the old trail is immediately next to this switchback.
0.79l36bush chinquapinChrysolepis sempervirens10 / 5
0.81r37pine lousewort (in area shielded by sugar pine roots of big tree with two small trees)Pedicularis semibarbata2 / 1
0.88r38Yosemite rockcressBoechera repanda10 / 1
0.89l(little prince's pine, Chimaphila menziesii, not seen here since 2005)
0.89The following three Mimulus species are only at this location in wet years (they are present in subsequent locations most years):
0.89b39Brewer's monkeyflowerMimulus breweri99 / 3
0.89b40floriferous monkeyflowerMimulus floribundus99 / 3
0.89b41false monkeyflowerMimulus pilosus20 / 2
0.89r(pinegrove groundsmoke, Gayophytum oligospermum)
0.89b42mountain California-fuchsiaEpilobium canum ssp. latifolium30 / 4
0.93r43shy monkeyflowerMimulus nasutus50 / 2
0.93l44groundsmokeGayophytum diffusum ssp. parviflorum10 / 1
0.94r45sticky cinquefoilDrymocallis glandulosa var. viscida50 / 3
0.94r46Idaho bentgrassAgrostis idahoensis50 / 3
0.94b47streambank lotusHosackia oblongifolia var. oblongifolia50 / 2
0.94r48fragile sheath sedgeCarex fracta30 / 9
0.94b(Fendler's blue grass, Poa fendleriana ssp. longiligula)
0.94l(deergrass, Muhlenbergia rigens, in drainage far below trail)
0.94r49bearded flatsedgeCyperus squarrosus4 / 1
0.94r50Suksdorf's monkeyflowerMimulus suksdorfii50 / 1
0.94r51Tiehm's rushJuncus tiehmii50 / 1
0.94r52long-styled rushJuncus longistylis15 / 3
0.95r53glaucus willowherbEpilobium glaberrimum ssp. glaberrimum30 / 2
0.95r54pinegrove groundsmokeGayophytum oligospermum30 / 3
0.95b55western azaleaRhododendron occidentale50 / 4
0.95b56Scouler's willowSalix scouleriana+20 / 5
0.95r57western marsh cudweed (waif)Gnaphalium palustre+1 / 1
0.95r58white catch-flySilene verecunda10 / 2
0.95r59mountain pink currantRibes nevadense30 / 4
0.95r60Parish's lupineLupinus latifolius var. parishii1 / 1
0.95r61willowherbEpilobium ciliatum ssp. ciliatum4 / 2
0.95r(hairy wood rush, Luzula comosa)
0.95Cross first small wet drainage (only one from Jolley Spring); elevation 7120 feet (2170 m)
0.95r62slender hairgrassDeschampsia elongata3 / 2
0.96r63broad-leaved lotusHosackia crassifolia var. crassifolia15 / 2
0.96r64California bee plantScrophularia californica10 / 2
0.97l65Parish's snowberrySymphoricarpos rotundifolius var. parishii30 / 5
0.97r(Fremont silk tassel, Garrya fremontii)
1.05rTree struck by lightning, which exited along its exposed root
1.08l(green-leaf manzanita, Arctostaphylos patula, in front of pink-bracted manzanita, Arctostaphylos pringlei ssp. drupacea, on ridgeline)
1.10l66hybrid manzanitaArctostaphylos patula X A. pringlei ssp. drupacea+2 / 2
1.12l67Jeffrey pinePinus jeffreyi+99 / 9
1.14r(clustered broomrape, Orobanche fasciculata)
1.14r68Fendler's blue grassPoa fendleriana ssp. longiligula10 / 1
1.19lDead tree with rocks 10 feet off ground  at top. How did the rocks get there? Try to explain it, then check our answer.
1.19l(Sierra gooseberry, Ribes roezlii var. roezlii, just below trail.)
1.20r69Parish's bedstrawGalium parishii20 / 4
1.24l(western wallflower, Erysimum capitatum var. capitatum)
1.24l70goldenrodSolidago velutina ssp. californica20 / 1
1.24l(thimbleberry, Rubus parviflorus)
1.24first location of Parish's snowberry, Symphoricarpos rotundifolius var. parishii, in 2011
1.25Note impressive rocks on other side of drainage.
1.25b71scarlet monkeyflowerMimulus cardinalis30 / 2
1.25r72Cleveland's horkeliaHorkelia clevelandii var. clevelandii+20 / 3
1.25r(arroyo willow, Salix lasiolepis)
1.25Cross small moist drainage #2 (first of four crossings of Powderbox Spring drainage); elevation 7320 feet (2230 m)
1.25b73western columbineAquilegia formosa50 / 3
1.25l74giant red paintbrush (died here in 2007)Castilleja miniata ssp. miniata10 / 3
1.25r75Fremont's goosefootChenopodium fremontii20 / 2
1.25best location for broad-leaved lotus, Hosackia crassifolia var. crassifolia
1.25r76granite prickly phloxLinanthus pungens38 / 4
1.25r77San Bernardino rubber rabbitbrushEricameria nauseosa var. bernardina+10 / 7
1.25r78Fremont silk tasselGarrya fremontii30 / 4
1.25l79narrowleaf bedstrawGalium angustifolium ssp. angustifolium5 / 3
1.26r80Martin's paintbrushCastilleja applegatei ssp. martinii6 / 3
1.26l81California coffeeberryFrangula californica+30 / 5
1.31l82*prickly lettuce (waif)Lactuca serriola+1 / 1
1.32r(bracken, Pteridium aquilinum var. pubescens)
1.35b83forest goosefootChenopodium atrovirens20 / 5
1.36l84branching phaceliaPhacelia ramosissima10 / 3
1.37r(blue elderberry, Sambucus nigra ssp. caerulea)
1.37l(only seen in 2012: tinker's penny, Hypericum anagalloides; baby clover, Trifolium sp.; June grass, Koeleria macrantha)
1.37Cross small wet drainage #3 (first of two of drainage containing Middle Spring; second is above Middle Spring); elevation 7380 feet (2250 m)
1.37r85baby brittle bladder fern (not seen since 2007)Cystopteris fragilis4 / 3
1.37r86green miner's lettuceClaytonia parviflora ssp. viridis12 / 1
1.37rVery small Mimulus nasutus and M. floribundus, just 2-4 cm (1-2 inch) tall
1.38r87Sierra gooseberryRibes roezlii var. roezlii15 / 4
1.41l88little prince's pineChimaphila menziesii6 / 4
1.42Seep in wet years
1.42r89thimbleberry (small plant never seen to bloom at this location)Rubus parviflorus30 / 3
1.42l90brackenPteridium aquilinum var. pubescens20 / 3
1.46lSecond location of hybrid manzanita, Arctostaphylos patula X A. pringlei ssp. drupacea
1.46Trail turns 90 degrees right.
1.48Cross bouldery drainage
1.50Switchback right, #5; elevation 7500 feet (2290 m).
1.54Cross same bouldery drainage again at higher elevation.
1.57r(white fir, Abies concolor, tree that fell over when it had a good-sized trunk, grew a new erect trunk which was lost, and now has two side branches competing to be the new main trunk)
1.59rView of Tahquitz Peak Lookout
1.60rView of Lily Rock, Palomar Mountain Range, San Diego County coastline, Santa Margarita Mountains and closer ranges.
1.66r(California chicory, Rafinesquia californica, seen only in 2010)
1.69Cross wet drainage #4, a large one ~80 feet above Middle Spring, second of the two crossings of this drainage; elevation 7600 feet (2315 m)
1.69r91blue elderberrySambucus nigra ssp. caerulea20 / 4
1.70Cross separate branch of same drainage
1.70l92red-stemmed spring beautyClaytonia rubra20 / 2
1.70lfirst mature brittle bladder fern, Cystopteris fragilis
1.76Trail turns left 50 degrees; tall rock walls on right.
1.80l(California cliff-brake, Pellaea mucronata var. californica)
1.80l93green-leaf manzanitaArctostaphylos patula50 / 9
1.81l94coyote tobacco (waif)Nicotiana attenuata+3 / 1
1.85Enter Powderbox Spring drainage with lots of western azalea, the best display of it on the trail.
1.85first live giant red paintbrush, Castilleja miniata ssp. miniata, in 2011
1.85l95Nevada cinquefoilDrymocallis lactea var. lactea30 / 2
1.85b96western wallflowerErysimum capitatum var. capitatum30 / 2
1.85Cross wet drainage #5, second of the four crossings of Powderbox Spring drainage; elevation 7680 feet (2340 m)
1.85First good stand of thimbleberry, Rubus parviflorus
1.85r(San Jacinto Mts. Keckiella, Keckiella rothrockii var. jacintensis)
1.86b97wax currantRibes cereum var. cereum50 / 4
1.91Switchback left, #6. (A blocked-off old trail continues down straight ahead.)
1.99Switchback right, #7, near drainage from Powderbox Spring again.
2.02Switchback left, #8, with a massive rock fortress above the switchback.
2.02r(Just off-trail beyond the switchback, in the boulders at head level and above, is San Jacinto prickly phlox, Linanthus jaegeri; and western polypody, Polypodium hesperium. ~25 feet farther to south is little-leaf mock orange, Philadelphus microphyllus, at trail level.)
2.02l98*bull thistle (waif)Cirsium vulgare+1 / 1
2.02r99Parish's campionSilene parishii10 / 2
2.04lSign: "Soil in the area is fragile. Please stay on the trail."
2.07r100musk monkeyflowerMimulus moschatus99 / 2
2.07r101San Jacinto Mts. keckiellaKeckiella rothrockii var. jacintensis10 / 3
2.07r102hairy wood rushLuzula comosa99 / 2
2.07Cross wet drainage #6, a small one immediately above Powderbox Spring; third of the four crossings of this drainage; elevation 7840 feet (2390 m); curve left
2.07r103vari-nerved sedgeCarex heteroneura5 / 1
2.07r(California geranium, Geranium californicum)
2.07r104changeable phaceliaPhacelia mutabilis+10 / 2
2.07r105mountain rock-cressBoechera retrofracta X+10 / 2
2.07bBest spot for Cleveland's horkelia, Horkelia clevelandii var. clevelandii
2.07r106blue-eyed grassSisyrinchium bellum+1 / 1
2.07r107larger mountain monkeyflowerMimulus tilingii30 / 1
2.07b108rigid hedge-nettleStachys rigida8 / 1
2.08r109Jepson's blue wildryeElymus glaucus ssp. glaucus5 / 2
2.08lView of Diamond Valley Reservoir, shaped like an hourglass.
2.08r110California groundconeKopsiopsis strobilacea30 / 2
2.13Trails turns 90 degrees right at ridge
2.14r(Many California groundcone, Kopsiopsis strobilacea)
2.20Switchback right, #9.
2.25l111southern mountain-monardellaMonardella australis ssp. australis5 / 2
2.25rTrail gradually bends left. Note the window formed by the boulders on right
2.27l112prickly hawkweedHieracium horridum10 / 1
2.27lBest location for mountain rock-cress, Boechera retrofracta X
2.27l(western polypody, Polypodium hesperium, just above head level hidden behind boulder between white fir and canyon live oak)
2.27l113Watson's spike-mossSelaginella watsonii5 / 1
2.27l114southern Sierra phaceliaPhacelia austromontana40 / 1
2.27l115small fescue (waif)Festuca microstachys1 / 1
2.27l116squirreltailElymus elymoides2 / 1
2.28l117rock buckwheatEriogonum saxatile5 / 1
2.35r(field of swamp sedge, Carex senta. Parish's yampah, Perideridia parishii, 30 feet below trail)
2.35Enter seep area
2.35l118long-anthered rushJuncus macrandrus80 / 1
2.35l119pearlwortSagina saginoides20 / 1
2.35l120Kentucky blue grassPoa pratensis ssp. agassizensis10 / 1
2.35b121California geraniumGeranium californicum5 / 1
2.35l122plain mariposa lilyCalochortus invenustus1 / 1
2.35l123lemon lilyLilium parryi+1 / 1
2.35l124glandular willowherbEpilobium ciliatum ssp. glandulosum2 / 1
2.35l125primrose monkeyflowerMimulus primuloides var. primuloides10 / 1
2.35lBest location for streambank lotus, Hosackia oblongifolia var. oblongifolia, in normal years
2.35l126abrupt-beak sedgeCarex abrupta10 / 1
2.35l127tinker's pennyHypericum anagalloides50 / 1
2.35Cross shallow drainage at head of Powderbox Spring drainage; last of the four crossings of this drainage; elevation 8010 feet (2440 m)
2.37Switchback left, #10. (on right: jct. with a blocked-off old trail; a path straight ahead leads to the hanging "picture window" rock seen from here; and six plants of San Jacinto prickly phlox, Leptodactylon jaegeri).
2.44r128San Gabriel beardtonguePenstemon labrosus10 / 1
2.44r(Elmer's needlegrass, Stipa occidentalis var. pubescens)
2.45r129pussy pawsCalyptridium monospermum20 / 1
2.52End Devils Slide Trail at Saddle Junction, 8075 feet (2460 m) elevation, a jct. with 4 other trails.
SPECIES ONLY FOUND OFF-TRAIL, which consequently were not numbered in the guide above, in order of appearance.
0.04130incense-cedar mistletoePhoradendron juniperinum1 / 1
0.19131oak mistletoePhoradendron serotinum ssp. tomentosum1 / 1
0.37132beautiful hulseaHulsea vestita ssp. callicarpha10 / 1
0.38133California elegant rock-cressBoechera californica1 / 1
0.40134short-flowered monardellaMonardella nana2 / 2
0.94135deergrassMuhlenbergia rigens5 / 1
1.14136clustered broomrapeOrobanche fasciculata6 / 1
1.25137arroyo willowSalix lasiolepis1 / 1
1.37138June grassKoeleria macrantha2 / 1
1.66139California chicory (waif)Rafinesquia californica1 / 1
1.80140California cliff-brakePellaea mucronata var. californica2 / 1
2.02141San Jacinto prickly phloxLinanthus jaegeri8 / 2
2.02142little-leaf mock orangePhiladelphus microphyllus1 / 1
2.02143western polypodyPolypodium hesperium2 / 1
2.35144swamp sedgeCarex senta50 / 1
2.35145Parish's yampahPerideridia parishii10 / 1
2.44146Elmer's needlegrassStipa occidentalis var. pubescens1 / 1

Comments On Specific Species

Pinus ponderosa, P. jeffreyi. These two similar yellow pines are easily discriminated on this trail by the length of the cones and elevation. P. ponderosa has small cones 6.5 to 9.5 cm (2.5 to 3.7 inches) long; P. jeffreyi cones are nearly twice as long, 12.0 to 17.2 cm (4.7 to 6.8 inches).

P. ponderosa is found at the trailhead up to mile 0.25 below an elevation of 6660 feet; most of the specimens in this area are at elevations below this trail. P. jeffreyi is found only on the upper part of the trail, beginning at mile 1.10 at an elevation of 7200 feet; most of the specimens in this area are in Tahquitz Valley above this trail.

See Pinus jeffreyi and P. ponderosa for a map of the distribution of these species on this trail, discussions of the unreliable commonly-used discriminants of these species, and pictures of the cones.

Corethrogyne filaginifolia. These plants key out to Corethrogyne filaginifolia var. glomerata in Munz. Also, some of these plants are unusual in having two-lipped corollas. The usual ligule is spreading, but the other ligule is erect, forming a cylinder around the disk flowers!

Quercus wislizeni var. frutescens. As far as we know, this is the highest elevation specimen of this species, at ~6500 feet. Munz gives an upper elevation of 5000 feet, and the Jepson Manual gives 2000 m = 6500 feet.

Ericameria nauseosa ssp. bernardina. The first occurrence of this species on trail in 2002 was no longer present in 2003, and has been removed from the guide. It was approximately at the location of the first off-trail specimen at mile 0.53.

Frangula californica. If one takes the taxa in the Jepson Manual seriously, there would be three on this trail:

Clearly, it is unreasonable to declare that there are three taxa on this trail, and we treat these all as F. californica, without subspecies.

Salix scouleriana. These were keyed out using blooms in April 2004, four plants from the drainage at mile 0.95 and one plant from the drainage at mile 1.23. All plants were males, and are only consistent with a S. scouleriana id from the JM staminate key.

The plants at mile 0.95 show a lot of similarity to Salix lasiolepis. The leaf margins are not uniformly turned down, which is more akin to S. lasiolepis than to the other S. scouleriana on the trail at higher elevation. Many of the leaves, especially on the young whips at the base of the taller trunks, are dead ringers for S. lasiolepis leaves, being elliptic/symmetric and thus very un-Scouler-like.

The plants at higher elevation all have leaves with uniformly-turned down margins, and are clearly all S. scouleriana, with the exception of the single off-trail location of S. lasiolepis at mile 1.28.

Arctostaphylos patula X A. pringlei ssp. drupacea. These specimens caused me great grief for their determination until I finally figured out and proved that these were hybrids of these two species. See Hybrids of Arctostaphylos patula and A. pringlei in the San Jacinto Mountains.

Dead tree with rocks 10 feet off ground near top of tree. Presumably, the ground level has not changed since the tree was alive, since the trunk/root junction is still at ground level. The area has the usual steep slope, so it is highly likely that the slope is the same as it always was, except for the trail construction.

Possible explanations:

Nick Nixon informs us that this tree is known as the Wishing Tree, and that he knows hikers that make a point of bringing a rock or two to throw at the tree. If the rock catches in the tree, those hikers believe their wish will be granted.

Tom picked up a rock, and lodged it in the tree with his first toss. (;-)

Horkelia clevelandii. The first occurrence on the trail is a single specimen that usually hides under a rock or another plant. The second occurrence at mile 2.04 has bunches of the plants.

Eriogonum apiculatum. Only in some years are plants of this species seen close to the trail, but a large population exists above the trail.

Phacelia mutabilis. There were a number of plants at mile 2.07 prior to 2007, when a gopher took out every single plant. Beginning about ten years later, a few plants have re-appeared in this first spot.

Sisyrinchium bellum. This plant is utterly invisible except for the few days when it has blooms in a given year. We're also not sure that it blooms every year.

Lilium parryi. This is the famous Munchkin Lemon Lily.

Bromus tectorum, Lactuca serriola, Cirsium vulgare. These non-native plants are probably waifs brought in by hikers or horses, and are weeded out when seen.

Cryptantha muricata, Eriogonum davidsonii, Gnaphalium palustre, Nicotiana attenuata, Stephanomeria virgata. These plants were only seen in a single one year, 2003, most with only a single specimen of each, and are probably waifs brought in by hikers or horses.

Boechera retrofracta X. There is no binomial name available for our plants that were formerly erroneously called Arabis holboellii. See Arabis = Boechera species with non-erect fruit.

Species that did not bloom in 2003:

Common NameLatin Name
Perennial species that were old enough to bloom, but did not bloom
Indian milkweedAsclepias eriocarpa
golden yarrowEriophyllum confertiflorum var. confertiflorum
Species with all plants too young to bloom in 2003, probably due to the 2001-2002 drought
California geraniumGeranium californicum
lemon lilyLilium parryi
larger mountain monkeyflowerMimulus tilingii
California beeplantScrophularia californica
hedge-nettleStachys rigida var. ajugoides

1 The Devils Slide Trailhead is the third highest trailhead in the Idyllwild Area. The higher two are:

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Copyright © 2002-2020 by Tom Chester, Dave Stith, James Dillane and Jane Strong.
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Updated 18 September 2020.